REN and anemia: These include the accumulation of uremic toxins, CKD-associated post-translational modifications and uremic lipids, as well as chronic low-grade inflammation and oxidative stress, endothelial cell dysfunction, hypercoagulability and altered platelet responses, cardiovascular calcification, activation of the renin–angiotensin–aldosterone system (RAAS) and the sympathetic nervous system, and anemia (Fig. 2).