EDNRA and cancer: Thus, several cancer cell lines, including HeLa, SKOV3, DU145, H1975, and A549—all of which expressed ETAR [31,32,33,34]—were applied to investigations of the anti-proliferative effects of Sal A. By CellTiter-Glo kit and RTCA assays, Sal A showed anti-proliferative effects in HeLa, DU145, H1975, and A549 cell lines with IC50 values under 20 μM.