To further explore whether tumor regression, and not erlotinib directly, was causing the observed changes in the immune microenvironment, we studied mice with EGFR mutant lung cancer induced by expression of the EGFRL858R + T790M mutant that is unresponsive to erlotinib treatment (Additional file 1: Figs. S3A and B) [34]. The gene discussed is EGFR; the disease is lung carcinoma.