Comparison of the clinical profiles of pneumonitis and non-pneumonitis patients showed that pneumonitis patients included significantly higher proportions of current or former smokers (37/530 vs. 7/240, respectively, P = 0.024), patients with pre-existing ILD (11/69 vs. 33/701, respectively, P<0.001) and with wild-type or EGFR not assessed (40/596 vs. 4/174, respectively, P = 0.027). This evidence concerns the gene EGFR and interstitial lung disease.