Yang et al. [105] demonstrated that 25 μM SFN induced autophagy in three triple-negative (ER-negative, PR-negative, and HER2-negative) breast cancer cell lines, namely, MDA-MB-231, BT549, and MDA-MB-468, as well as suppressed HDAC6 expression, resulting in phosphatase and tensin homolog (PTEN) activation. Here, PGR is linked to breast cancer.