According to a 2013 meta-analysis of epidermal expression frequencies in NSCLC, the frequencies (EGFR) gene mutations are 47.9% and 19.2% in adenocarcinomas and 4.6% and 3.3% in squamous cell carcinomas in Asians and Westerners, respectively, according to a 2013 meta-analysis (mut MAP) of EGFR mutation expression frequency in NSCLC [16]. Here, EGFR is linked to squamous cell carcinoma.