(Capcom's primary storyline)
The Mold is a fungal superorganism which was developed by The Connections in the 1990s as part of their Bio Organic Weapons research. The purpose of the Mold was a means of mind control, with a genetically-engineered human mentally controlling others.
The Mold was developed in 2000 by The Connections in a joint project with H.C.F. to develop a new form of bioweapon. It was a success in terms of a bioweapon, since it could turn enemies into allies, or hostiles into servants, eliminating the costs of sheltering prisoners-of-war and even combat, gathering negative attention from the bioweapon market.
Fabrication and results
To fabricate the Mold, its genome should be introduced to a pre-Stage 4 human embryo under cultivation over a period of 38 to 40 weeks. To ensure blending into crowded populations without effort, these humans were always female and were artificially aged to the appearance of a ten year old.
Over several years five lines of human B.O.W.s were created, each better able to control the Mold and blend into human society. Each was given a letter-number designation to determine their position in the line, starting from A-E. The prototype E-Type, "E-001" - otherwise known as Eveline - showed remarkable abilities. Another astonishing feature was that Eveline was capable of a profound imposition over the body and mind of those personally chosen to be living hosts of the Mold. The creators of the bioweapons theorized that the mind control was possible much alike the action of autoinducer pheromones used for quorum sensing in Pseudomonas bacteria.
In further analysis of Eveline's abilities, immediately after infection, subjects showed to see images of her, even though she was not present, having their will bent from companionship or assistance requests to self-mutilation or hostile behavior. Infected subjects also stated a schizophrenic state where the person hears Eveline's voice, even though it's inaudible to anyone else. This psychological shock helps to break down the mind's natural barriers and open the way to Eveline's brainwashing abilities.
The E-Type is capable of developing from his or her mutamycete's mycelia, the fungal filaments inserted during the aforementioned process, the bacterium, superorganisms formed of countless mycelia. This is the agent responsible for the infection of other individuals and the cause to symptoms stated above, being extremely resistant and contagious. Hereafter, the bacterium is referred as mold, and the subjects were called by the researchers as Molded, in a nod to be made of mold, but also in the meaning of "molded", as in "shaped".
As Eveline was the first and only E-Type subject before the events of Resident Evil 7: Biohazard, the reports take in consideration the effects caused by her actions.
According to the Infection Report, the initial infection occurs when the mold ingests nutrients from the subject's body to propagate itself, and slowly takes over cells within the body, causing, as a side effect, remarkable regenerative abilities. Subjects infected are capable of coapting legs and arms within minutes if severed. This is due to the fungus' secretion of a telomerase-like enzyme through the cell walls, which causes the activation of the ERK pathway, and thus, forces cell-division to regenerate damaged tissue until their natural limit. However, not every subject possess the same healing capabilities, as Jack Baker is notably more resilient than any of the other subjects. Mentally, the subject still maintains its mental state and has little to no physical changes.
Once the mold reaches the brain, a mind connection is made with the E-Type asset, allowing the infected to experience the aforementioned hallucinations, including images of the asset and hearing voices. This can lead to hostile behavior, and eventually the infected become so connected with the E-Type that a process of losing its individuality starts, losing all of its sense of ego. some also get other abilities such as heighten senses, super intelligence, amazing strength, or creating and controlling bugs as seen with the Bakers and Mia.
This stage develops when the body of an infected individual suffers severe damage. In Jack Baker's case was losing the upper half of his body, and in Lucas' was a shot to the head with the Albert-01. The mold takes every cell in the body causing severe physical changes, leading to the infected to lose their human form. The mutations differ from case to case, but all resulting in him or her acquiring incredible physical strength. To contain a subject in this state is considered to be extremely difficult.
The only known cure to the state of infection by the mold is by a serum produced by a method that uses samples of the E-Type body tissue, producing a unique fungicidal serum, capable of destroying the cells of any subject infected by results of E-Type bioweapon model. However, if the subject has reached the final stage of infection, injection of the serum is fatal.
The pattern effect of the toxin is to calcify every cell that has been infected with the mold. As the infected in initial stages do not have a high number of cells corrupted by the mold, the fungicidal serum is advised to those at this point of contamination, since the calcification will have a small impact on the subject's health.
As higher stages include infection in the brain or in every cell of the body, if the serum is injected into an individual afflicted by the mold at this stage, the result is certain death, by the calcification of every cell. For that reason, the fungicidal serum is primary use of the disposal of initially infected subjects, rather than a cure.
In exploring the serum's potential, a currently unknown process is capable of enchancing its effects to extreme potency, becoming a compound known as E-Necrotoxin. Even in tiny amounts, according to R and D Report (2 of 2), seems to bring an unknown effect due to the censorship in the document. In 2017 the E-Necrotoxin was used on Eveline by Ethan Winters, but instead of calcifying her body and killing her outright, she instead merged into nearby Mold to create a new body. It evidently caused Eveline great measure of pain, to the point liquefying her, seemingly deteriorating her down to the molecular level. It nevertheless failed to truly finish her off and only triggered Eveline's final desperate transformation to ensure suitability. It is however, potent enough to have her vulnerable to death via physical shock, allowing for her calcification upon being rained down with bullets by Ethan.
- The Mold's history is portrayed differently in the localized versions of the game. The NEXBAS Project is not described in the original Japanese script, while the compound word "mutamycete", which means "changing fungus", does not appear at all. Instead, the Japanese script uses the word kin (菌), which simply means "fungus".