We generated whole cell extracts (WCEs) from one of the cancer cell lines in which PRDM9 gene expression had been observed, NTERA-2 (Fig. 1A), and a culture of non-cancerous primary human prostate smooth muscle (HPrSM) cells, in which no PRDM9 gene expression could be detected by RT-PCR. The gene discussed is PRDM9; the disease is cancer.