CCL2 and rheumatoid arthritis: Despite having higher basal levels of inflammatory and bone-associated genes, ORF8-treated RA-hOBs showed increased expression of inflammatory genes — IL6, IL17A, IL17F, TNF, and CCL2 — as well as bone-associated genes — RANKL, OPG, RANKL/OPG ratio, PTH1R, ALP, COL1A1, and collagen type XVII α1 chain (COL17A1) — when compared with ORF8-treated H-hOBs (Figure 5C and Supplemental Figure 2, C and D).