Thus, these results showed that HOXA2 and additional transcription factors mediate the regulatory effect of the risk SNP at the 19q13 locus on PCAT19 and CEACAM21 and eventually lead to aggressive prostate cancer susceptibility [73] and also raise new questions of how these transcription factors compete for the binding to the SNP region. The gene discussed is CEACAM21; the disease is prostate cancer.