On the contrary, other studies indicated that no significant differences in the plasma MTX concentrations were found for the different MTHFR C677T genotype in lymphoma (19), which was in line with our results in regard to which we found that the plasma MTX levels at 48 h were independent in both C677T and A1298C polymorphisms (Table 4). The gene discussed is MTHFR; the disease is lymphoma.