PIN1 and triple-negative breast carcinoma: Treatment of MDA-MB-231 triple negative breast cancer (TNBC) cell lines with the recently identified PIN1 inhibitor all-trans retinoic acid (ATRA), which binds to the PIN1 active site and degrades PIN1 [41], decreased the levels of FAAP20 in a dose-dependent manner, as well as the levels of AKT, a known target of PIN1, without significantly affecting cellular viability [42] (Fig 8A and S7D Fig).