The effect of DHLA on the PDGFR pathway and phosphatases. A) p-PDGFR after PDGF stimulation at various time points. n = 3 NL and SSc subjects. Enzymatic activities of PTP1B (B), SHP-2 (C), and DEP-1 (D) in fibroblasts with or without DHLA or NAC. Results are expressed as mean ± S.E. and p < 0.05 was considered significant.