Several observations suggest that LRIG1 tumor suppression is dependent on RTK-RAS-RAF signaling: First, in mice with a Kras-activated background, the most frequently mutated gene involved in progression from colon adenoma to adenocarcinoma was Lrig1 [16], suggesting that Lrig1 suppresses early malignant transformation in this context. The gene discussed is LRIG1; the disease is colon adenoma.