HIF1A and osteoarthritis: “MANALO_HYPOXIA_UP” (genes up-regulated in response to both hypoxia and overexpression of an active form of HIF1A), another candidate biological gene sets associated with SIS, played a vital role in the pathogenesis of osteoarthritis (OA) and rheumatoid arthritis (RA) (Johnson et al. 2000; Brouwer et al. 2009; Pfander et al. 2006).