PIM1 and osteoarthritis: Compared with the target proteins of quercetin, there were three common members, protooncogene serine/threonine-protein kinase Pim-1 (PIM1), cytochrome P450 1B1 (CYP1B1), and heat shock-related 70 kDa protein 2 (HSPA2), which were considered as the key proteins during the treatment of osteoarthritis by quercetin.