We first examined expression levels of five jumonji histone demethylase genes included in JARID family, KDM5A (JARID1A), KDM5B (JARID1B), KDM5C (JARID1C), KDM5D (JARID1D) and JARID2, in a small subset of clinical bladder cancer samples and found a significant difference in expression levels between normal and cancer cells only for the KDM5B gene (data not shown). The gene discussed is KDM5D; the disease is cancer.