HRAS and neoplasm: To address this possibility, we employed a tumor allograft model in which athymic mice were injected subcutaneously in each flank with Ras stable cells, and resultant tumors were resected after 20 days.42 We assessed membrane microdomain distribution of H-Ras variants in tumor lysates ex vivo, and found that the tR shifted H-Ras to the Lo domain, indicating that the predicted membrane microdomain distributions of these Ras variants were upheld in the tumor cells in vivo (Figure 5a).