For reasons that remain unclear, mutations in the PRKAA2 gene are particularly frequent in human skin cancer and melanoma, where, in several different studies, they occurred in 10–23% of cases, while amplification of PRKAA1 is common in adenocarcinoma and squamous cell carcinoma of the lung, where it has been found to occur in 8–11% of cases [140]. The gene discussed is PRKAA2; the disease is skin cancer.