Other relevant findings include higher RBC MTX PG levels in AA homozygous RA patients compared to other genotypes (P = 0.007) [168], higher MTX plasma levels in AA children with acute lymphoblastic leukemia (P = 0.004) [169] and lower uptake of MTX in CD4+ T cells and B cells in healthy individuals expressing the GG genotype, compared to those having the A allele [170]. This evidence concerns the gene CD4 and rheumatoid arthritis.