JQ1 was originally developed as an antitumor drug via a small molecule screen, and has proven effective in treating in vivo models of acute myeloid leukemia, multiple myeloma and nuclear protein of the testis (NUT) midline carcinomas (reviewed in Filippakopoulos and Knapp, 2014; Wang and Filippakopoulos, 2015). This evidence concerns the gene NUTM1 and plasma cell myeloma.