ESR1 and breast cancer: In our screen of additional breast cancer cell lines, the LOF of SRC enhanced TRAIL-induced caspase-3/7 activation by 2 or more standard deviations in the two TNBC cell lines MB231 and MB468, and by 1 standard deviation in the ER-positive cell line T47D (Figure 5, Table 1, and Additional file 8: Table S4).