GSTM1 and Alzheimer disease: Mutation in the gene encoding apolipoprotein E (substitution of cysteine with arginine—an amino acid lacking thiol groups) is a susceptibility biomarker for Alzheimer’s disease [18], while homozygous deletion of GSTT1 and combined deletion of GSTT1-/GSTM1- was found in patients sensitized by thimerosal (Westphal’s group) [132].