Several independent in vitro studies have demonstrated the inhibitory action of progesterone on breast cancer cell growth [6–8] and in agreement with these findings in a very recent paper we report that hydroxyprogesterone (OHPg), via PR-B isoform, leads to a reduced cell survival due to autophagy induction [9] through PTEN up-regulation. The gene discussed is RB1; the disease is breast carcinoma.