Various studies have linked the KDM5s to different cancers, in particular overexpression of KDM5B has been observed in prostate, gastric, breast, ovarian and hepatic cancer cells.4 KDM5B also has a role in development by blocking differentiation of embryonic and hematopoietic stem cells.5 The KDM5s have therefore become increasingly popular targets for chemical probe and drug discovery to gain a greater understanding of their role in biology and as oncology targets. Here, KDM5B is linked to cancer.