MTHFR and neoplasm: Tumour folate predicted altered tumour serine (Model 3: beta: −3.12, p = 0.026) and glutamine (Model 2: beta: −0.95, p = 0.043) after multivariable adjustment of age, sex, smoking status, BMI, plasma folate, genomic LINE1 methylation, and MTHFR 677CT/TT genotype (Figure 2G).