PDZK1 and osteoarthritis: For example, PDZK1 can regulate the absorption of carnitine by the organic cation transporter (OCTN) in the intestine, regulate the transport of glycylsarcosine by the oligopeptide transporter (PEPT2), and participate in the regulation of the urate/anion exchanger (URAT1) in renal tubular uric acid reabsorption.[12, 13, 14] Notably, a recent study has shown that PDZK1 loss promotes chondrocyte senescence in osteoarthritis.[15] However, the role of PDZK1 in DR pathogenesis remains to be further elucidated.