Immune microenvironment features and efficacy of PD-1/PD-L1 blockade in non-small cell lung cancer patients with EGFR or HER2 exon 20 insertions.

NSCLC patients with EGFR/HER2 Ex20ins had similar genomic characteristics and distinct immune features. Patients with EGFR Ex20ins had significantly higher PD-L1 expression than those with HER2 mutations, which may be the potential reason for the different responses to PD-1/PD-L1 blockage.