MUC1 and idiopathic pulmonary fibrosis: This was also the case when these patients were stratified by sex, being serum KL-6 levels similar between women with ASSD-ILD+ and those with IPF and also between men with ASSD-ILD+ and those with IPF (1383.20 ± 993.93 U/mL vs. 1561.14 ± 894.01 U/mL, p = 0.87; 2232.91 ± 1312.30 U/mL vs. 1707.91 ± 965.94 U/mL, p = 0.12, respectively).