MTHFR and non-small cell lung carcinoma: This result was supported by a number of previous studies that have discovered a correlation between MTHFR variants and the efficacy or toxicity and survival time of advanced NSCLC patients who received pemetrexed plus platinum treatment (Smit et al., 2009; Li et al., 2013; Krawczyk et al., 2014; Li et al., 2014; Ding et al., 2017).