SHMT1 and cancer: SHMT2 has been shown to be a crucial factor in the serine/glycine metabolism of several cancer cell types, including colon and breast, and thus represents a hot target for selective anticancer drugs.12 Lung cancer is the second most common cancer expected to occur in men and women in 2014 and the first leading cause of cancer-associated deaths worldwide.13 Recently Zhang et al.14 demonstrated that SHMT1 is overexpressed in tumor-initiating lung cancer cells, suggesting that the function of this gene could be cancer cell type specific.