FGFR1 and breast cancer: Similarly, PD173074, an FGFR1/FGFR3 dual inhibitor, was shown by Koziczak et al. 25 to block cell cycle progression in MDA-MB-453, MDA-MB-415, and SUM52 breast cancer cell lines through modulation of Cyclin D1, while Azuma et al. 26 determined that PD173074 induced apoptosis in a lapatinib-resistant breast cancer cell line (UACC812/LR) via an EGFR-independent mechanism25, 26.