Consistent with data from analysis of in vivo tumours, knockout of ARID1A in the human prostate cancer DU145 cells significantly promoted growth, increasing cell counts in DU145 ARID1A knockout KO2, KO4 clones and KO pool cells by 68%, 45% and 38% respectively (Supplementary Fig. 5, Fig. 3f). The gene discussed is ARID1A; the disease is neoplasm.