ITGA1 and papilloma: When the dissected cSCC suspects were histologically graded, 64% (n = 9/14) of those in the Itga1+/+ mice represented cSCCs of grades 1–3, and 36% (n = 5/14) represented benign or dysplastic papillomas, whereas in the Itga11−/− mice, 29% (n = 2/7) of tumors were eventually scored as cSCCs, and 71% were scored as (n = 5/7) as papillomas (Supplementary Table 4).