ERBB2 and pneumonitis: In multivariable models, pre-treatment ILAs (HR 10.56, 95% CI 3.8-29.31, p < 0.0001) and HER2 (HR 0.30, 95% CI 0.09–0.96, p = 0.042) were the strongest predictors of pneumonitis, with a marginal association observed for V20 (HR 1.04, 95% CI 0.99–1.09, p = 0.081).