SELENOI and breast cancer: To ascertain whether it is the increase of PE or TAG that mediates Src-dependent cell growth, breast cancer cells were knocked down of ethanolamine phosphotransferase-1 (EPT-1) to reduce PE biosynthesis (Fig. 3h and Supplementary Fig. 8v), and/or treated with the DGAT inhibitors PF-04620110 (DGAT1 inhibitor) and PF-06424439 (DGAT2 inhibitor), to inhibit TAG biosynthesis (Supplementary Fig. 8w).