MTAP and cancer: In transformed DLBCL, the S-methyl-5’-thioadenosine phosphorylase (MTAP) gene encoding for a critical methionine metabolism enzyme is deleted due to its proximity to the tumor suppressor gene CDKN2A (Dreyling et al., 1998), and this phenomenon sensitizes cancer cells to PRMT5 inactivation (Marjon et al., 2016).