CD4 and cancer: We previously reported that cell death plays significant roles in activated T cells (20, 56, 100–102), CD4+Foxp3+ Tregs in vascular inflammation (18, 19), activated ECs in atherosclerosis (8, 11, 33, 103), MI (104), angiogenesis (105), activated VSMCs in neointima hyperplasia (12), non-alcoholic fatty liver disease (106), ischemia-reperfusion in the liver (107), and ultrasound-treated cancer cells (57, 108, 109).