The first report suggesting a role for progranulin in conferring resistance to chemotherapy was in breast cancer, as Tangkeangsirisin et al. observed that progranulin counteracted tamoxifen-induced apoptosis in breast cancer cells by inhibiting bcl-2 downregulation and preventing poly (ADP-ribose) polymerase cleavage [137]. This evidence concerns the gene GRN and breast carcinoma.