CD4 and atherosclerosis: Depending on the expression of specific transcriptional factors or variations in the local cytokine milieu along with antigen presentation, naïve CD4+ T cells differentiate into different Teff lineages, including T helper type 1 (Th1), T helper type 2 (Th2), and T helper type 17 (Th17) lineages, which have critical roles in the development of atherosclerosis in mice and humans [1].