STAT3 and osteoarthritis: In the rat model of osteoarthritis induced by monosodium iodoacetate, intravenous and intra-articular administration of human adipose tissue-derived MSCs (hAD-MSCs) can reduce the expression of pro-inflammatory cytokines in joints by inhibiting signal transducer and activator of transcription 3 (STAT3) signaling pathway, thus improving cartilage damage and restoring osteoarthritis-related mechanical allodynia and thermal hyperalgesia [10].