MTHFR and non-Hodgkin lymphoma: As shown in Table 2 and Figure 2, pooled analysis did not yield a significant association between MTHFR C677T polymorphism and overall NHL risk (homozygous: OR = 1.06, 95% CI = 0.93–1.20; heterozygous: OR = 0.97, 95% CI = 0.89–1.07; recessive: OR = 1.04, 95% CI = 0.95–1.15; dominant: OR = 0.99, 95% CI = 0.90–1.08 and allele comparing: OR = 1.01, 95% CI = 0.94–1.08).