Tedjarati et al(26) reported that the subcutaneous injection of 7,000 IU per week of PEG-IFN-α2b into nude mice bearing human ovarian cancer cells induced a significant decrease of CD31-positive endothelial cells and Huang et al(27) showed similar results with the subcutaneous injection of 70,000 IU per week of PEG-IFN-α2b on human prostate cancer cells. Here, PECAM1 is linked to prostate cancer.