Only three previous studies have used whole-exome sequencing (WES) to study AK; these studies have included ≤10 samples and reported similar mutational spectra in AK and cSCC with frequent mutations in known cSCC tumor suppressor genes TP53, NOTCH1, NOTCH2, and FAT1 (Albibas et al., 2018; Chitsazzadeh et al., 2016; Rodríguez-Paredes et al., 2018) (Supplementary Table S2). Here, NOTCH1 is linked to skin squamous cell carcinoma.