[6] James, while at the NCTR, conducted research on the role of DNA methylation and cancer susceptibility, and also studied metabolic differences in children with Down syndrome.
She originally received a grant from the EPA to conduct this research in 2004,[9] and presented preliminary results the following year, in which she reported that the Fallon children have a metabolic predisposition to develop leukemia, though the cancer itself is caused by environmental contaminants.
[13] She has also found that administering these compounds as supplements, as well as methylcobalamin and folinic acid, to autistic children can significantly restore their levels of glutathione and cysteine and may therefore be useful in the treatment of autism.
At the time the grant was being awarded, Johnson herself said that "Jill James' work at ACHRI holds great promise for the future of autism therapy and prevention.
"[25] Another field of her research that has attracted attention is a number of in vitro studies she has conducted regarding the toxicity of thimerosal to neuronal and glial cells; which, she has concluded, is mediated by glutathione.