Short stimulation with low-concentration TGF-β1 (1 ng/ml for 6 and 24 h) induced TGF-β1 mRNA and protein only in SSc-MSCs but not H-MSCs [32], further emphasizing different kinetics in the autocrine TGF-β1 loop of SSc-MSCs and H-MSCs. Here, TGFB1 is linked to systemic sclerosis.