Based on the observations that ID4 promotes multiple anti-cancer pathways such as apoptosis and androgen receptor activity, we therefore tested the hypothesis that a combination of DTX, the first line chemotherapy for advanced prostate cancer [24, 25] and ID4-NC could have a synergistic effect on the regression of tumors than when treated with either DTX or ID4NC alone. The gene discussed is AR; the disease is prostate carcinoma.