Controversially, Jarid1b has been reported as an epigenetic regulator with tumour‐suppressive potential in melanoma.30 A slow‐cycling melanoma cell subpopulation was shown to be characterized by high Jarid1b expression.31 In leukaemia, high expression of Jarid1b promotes cell differentiation, showing tumour‐suppressive potential rather than acting as an oncogene. The gene discussed is KDM5B; the disease is leukemia.