Spline models for PFT correlation with OS and PFS. The solid line (vertical axis) represents log (HR) for PFS/OS. The shaded area represents the 95% CI. Thresholds were graphically demonstrated as the points at which the 95% CI crossed 0. (A) Spline model for FEV1 correlation relation with OS. (B) Spline model for DLCO correlation with OS. (C) Spline model for FEV1 correlation with PFS. (D) Spline model for DLCO correlation with PFS