In fact, several HMT/HDMTs, BET bromodomain, HDACs [40], and DNMT inhibitors are currently under clinical or pre-clinical stages in PCa [125,126], some of which have been approved by the FDA for other malignancies such as myelodysplastic syndrome (MDS), acute myeloid leukaemia (AML) or acute lymphocytic leukaemia (ALL) [127] (Table 1). This evidence concerns the gene HNMT and myelodysplastic syndrome.