Important epigenetically silenced genes in SCLC include NEUROD1, REST, TF2 (TCF2/HNF1B), retinoic acid receptor beta (RARB), and BCL2. Further genes located in the critical chromosomal region 3p include RASSF1A and enhancer of zeste homologue 2 (EZH2) [137, 138]. The gene discussed is RARB; the disease is small cell lung carcinoma.