In non-squamous NSCLC, detection of deleterious mutations within the PTPRD phosphatase domain in ctDNA has emerged as a predictive biomarker identifying patients who derive greater benefit from ICI therapy than from chemotherapy, regardless of TMB, PD-L1 status, or TP53/KRAS/EGFR mutation background [69]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.