Anti‐IL‐17RA mAb administration also downregulated fibrosis‐related gene (α‐SMA, Postn, Col1A1, Col3A1, Ctgf, Fn1, Timp1, and Vimentin) expression in BLM‐SSc mice and upregulated the expression of collagen degradation‐related genes (Mmp3 and Mmp9) (Figure S13, Supporting Information). Here, COL3A1 is linked to systemic sclerosis.