Quantitative RT-PCR analysis in our study confirmed that, as expected, treatment of pulmonary fibrosis in mice with the optimal effective dose of PFD (100 mg/kg) increased RGS2 mRNA levels in mouse lung tissues (Fig. 4A, p < 0.05, n = 3), and RGS2 mRNA levels in the hUC-MSCs combined with P30 group were more elevated than those in the P100 group (p < 0.05, n = 3). Here, RGS2 is linked to pulmonary fibrosis.