APC and skin basal cell carcinoma: It may be noted that the magnitude of overexpression of the genes involved in the PD-L1 expression and PD-1 checkpoint pathway was more marked (interaction p = 5.2 × 10−21) in patients with BCC who had BCC-associated DELs in APC [FC = 2.9 (95% CI 2.5–3.4); see Figure 4B] compared to patients without APC DELs [FC = 1.4 (95% CI 1.2–1.6); see Figure 4A].