Having identified the expression properties of STIM1 and ORAI1 in human prostate tumor tissues, we next examined their expression level in four human prostate cell lines, i.e., BPH-1, LNCaP, DU145 and PC3; BPH-1 is a hyperplasia cell line, and the latter three are cancer cell lines with increasing propensity for metastasis32. This evidence concerns the gene STIM1 and cancer.