More than 50% of NSCLCs with KRAS mutations present another mutation, and three subgroups can be established: the KP subgroup has mutations in tumour protein 53 (TP53) and represents 40% of cases; the KL subgroup, where serine/threonine kinase 11 (STK11), Kelch-like ECH-associated protein 1 (KEAP1) or liver kinase B1 (LKB1) is identified, is usually associated with low percentages of PD-L1; and the KC subgroup, which is characterized by inactivation of CDK2A/B, is associated with a mucinous histology [60, 61]. The gene discussed is STK11; the disease is keratoconus.