No significant between-study heterogeneities were observed among the overall studies for the association of SHMT1 C1420T polymorphism with NHL risk (allelic comparison: P = 0.29; homozygote model: P = 0.07; dominant model: P = 0.65; heterozygote model: P = 0.64), except for the recessive model (P = 0.04). Here, SHMT1 is linked to non-Hodgkin lymphoma.