With the purpose of validating the in vivo significance of HMGA1-induced upregulation of FKBP12 and resultant susceptibility of cells to rapamycin, we established a syngeneic tumor transplantation model by inoculating mouse-derived esophageal cancer cell AKR, along with AKR cells stably silenced for HMGA1 using shRNA, into the axillary region of C57BL/6 mice. The gene discussed is HMGA1; the disease is neoplasm.