The DVSMCs of SSc patients were isolated and incubated with IL-9, IL-9 neutralizing antibody, SSc serum, SSc serum and IL-9 neutralizing antibody, tanshinone IIA, IL-9, and tanshinone IIA, and SSc serum and tanshinone IIA for 3 days. This evidence concerns the gene IL9 and systemic sclerosis.