Since PDCD5 expression was increased in the lungs of patients with IPF and in the lungs of mice with fibrosis, we examined whether CK2-mediated phosphorylation of PDCD5 at Ser-119 is required for PDCD5 stabilization and nuclear translocation in response to TGF-β1. Here, PDCD5 is linked to idiopathic pulmonary fibrosis.