To guide treatment selection include EGFR mutations, ALK fusions, BRAF V600E mutation, ROS1 fusions, RET fusions, MET amplification or MET exon 14 skipping variants, ERBB2 (HER2) mutations, NTRK fusions, PD-L1 expression and tumor mutational burden (TMB) level (https://www.nccn.org/professionals/physician). The gene discussed is ERBB2; the disease is neoplasm.