Fig. 2

Kaplan–Meier survival curves for CC16 in IPF and AE-IPF patients. A Patients with IPF were divided into CC16 low group and CC16 high group according to the minimum P-value between the two groups, the optimal cut-off value was 67.4175 ng/ml, then Kaplan–Meier survival analysis was used to analyze the survival difference between the two groups. B Kaplan–Meier survival analysis was conducted between low CC16 and high CC16 group in patients with AE-IPF, the optimal cut-off value was 129.655 ng/ml. C The CC16 low group and high group were grouped again according to age, and the survival difference among the groups was analyzed by Kaplan–Meier analysis. D The survival differences were compared between different CC16 level and different gender. E Kaplan–Meier survival analysis between different CC16 level and different smoking status