PLK2 expression decreases in patients with pulmonary fibrosis; Primary fibroblasts with PLK2 KO shows myofibroblast phenotype; The expressions of OPN, IL-18, ACTA2, COL1A1 and COL3A1 in the lung tissues of PLK2 KO mice are significantly increased; And drug inhibition of PLK2 in human lung fibroblasts leads to a fibrotic phenotype (52). Here, PLK2 is linked to pulmonary fibrosis.