Though we summarized the involvement of PD-1 and PD-L1 or PD-L2 molecules in the pathogenesis of the different primary vasculitides (Table 1), the key content of this review is majorly subjected to a deep-seated awareness and a knowledge acquisition on the role of the PD-L1/PD-1 axis in various pathomechanistic and clinical aspects of atherosclerotic blood vessel inflammatory diseases—in particular, CAD, PAOD, CS, MI and stroke. The gene discussed is CD274; the disease is Cowden syndrome 1.