To confirm that Δ133p53β can regulate CD274 expression in prostate cancer, CD274 mRNA expression was quantitated in PC3 p53 null cells transiently transfected with a Δ133p53β plasmid, or Δ133p53 levels reduced with an siRNA in 22Rv1 prostate cancer cells. The gene discussed is TP53; the disease is prostate cancer.