In our study we found a robust enhancement of one-carbon metabolism enzymes but also the up-stream SSP enzymes in the two main subtypes of lung cancer on the mRNA level and an association of MTHFD1 and MTHFD2 gene expression with poor survival in lung adenocarcinoma, in line with previously published reports [22–25]. The gene discussed is MTHFD1; the disease is lung adenocarcinoma.