The results of hematoxylin-and-eosin staining showed that there was no significant difference in the lung between Prmt9WT and Prmt9CKO mice without VSV infection, and PRMT9 deficiency alleviated inflammatory cell infiltration, tissue edema and pulmonary fibrosis compared with the Prmt9WT mice following VSV infection (Fig. 3g). Here, PRMT9 is linked to pulmonary fibrosis.