YC-1, an early identified HIF inhibitor, operates by diminishing the expression of HIF-1 target genes, including VEGF and inducible nitric oxide synthase (iNOS), through suppression of HIF-1α stability and transcriptional activity under hypoxic conditions, thereby modulating inflammatory responses and vascularization in RA (211). Here, HIF1A is linked to rheumatoid arthritis.