SFTPD and pneumonitis: SP‐D and %DLCO levels differed significantly between patients with and those without severe pneumonitis (125 ng/mL, IQR = 66.0–156.0 vs. 51.6 ng/mL, IQR = 30.3–87.5, p = 0.0079; Figure 2a, and 58.8%, IQR = 50.8%–91.9% vs. 91.3%, IQR = 78.0–109.8, p = 0.0087; Figure 2b, respectively).