CD4 and age-related macular degeneration: Cruz-Guillory et al reported the presence of T helper 17 (Th17) cells (effector CD4+ T cells), which preferentially produce IL-17, after oxidative damage induced by eye injection of the AMD-associated lipid peroxidation product carboxyethylpyrrole (CEP) and demonstrated that these cells promoted M1 polarization in vitro [7].