The large-scale prospective study of the postoperative AE-ILD by the JACS demonstrated seven risk factors: (i) male sex, (ii) preoperative steroid use for ILD, (iii) previous history of AE, (iv) radiological UIP pattern, (v) %VC less than 80%, (vi) elevation of the serum KL-6 level, and (vii) surgical procedure besides segmentectomy [7]. Here, MUC1 is linked to idiopathic pulmonary fibrosis.