EGFR and cancer: Among these nine individuals, EGFR plasma copy numbers ranged from 2.37 to 143.94 (1+ [n = 1], 2+ [n = 4], and 3+ [n = 4]) across six different cancer diagnoses: tonsillar squamous cell carcinoma (n = 1), triple-negative breast cancer (n = 1), adenocarcinoma of unknown primary (n = 1), gastroesophageal junction adenocarcinoma (n = 1), adrenocortical carcinoma (n = 2), and colorectal cancer (n = 3).