For EGFR mutation testing, 19 studies used tumor tissue samples [1, 4, 12, 14–16, 19, 20, 23, 24, 26–34], six studies cytological materials [1, 11, 13, 16, 18, 25] and three studies blood samples [18, 21, 34], with four studies using more than one type of samples [1, 16, 18, 34] and two not specifying the specimen types [17, 22]. Here, EGFR is linked to neoplasm.