FASLG and cancer: Although we failed to detect m-CD95L at the plasma membrane of human MDA-MB-231 and mouse 4T1 TNBC cells (Figure S1C), we could not rule out that an undetectable amount of m-CD95L still engaged CD95 in an autocrine fashion to induce basal signaling, which was abrogated by the loss of CD95 in cancer cells.