HOXA7 and neoplasm: To determine whether the ANTP-SmacN7 protein could enter tumour cells, the concentration of the polypeptide entering EC109 cells was measured by FITC fluorescence intensity, which corresponded to 1 × 10−5, 1 × 10−6 and 1 × 10−7 M of SmacN7, ANTP-SmacN7 and ANTP entering into EC109 cells, respectively.