Transformation to SCLC is associated with mutations in several epigenetic regulators, such as members of the KMT2 family of lysine methyltransferases [9,55], and upregulation of various epigenetic and chromatin remodeling enzymes, such as EZH2 and other members of polycomb repressive complex 2 (PRC2) [55]. This evidence concerns the gene EZH2 and small cell lung carcinoma.