In order to test activation of autophagy in sorafenib-resistant AML cells, sorafenib-resistant cell lines were built such as Baf3 cells with FLT3-D835Y or FLT3-ITD + D835Y mutation and detected the expression of autophagy markers including LC3B, Beclin-1, ATG5 and p62. The gene discussed is ATG5; the disease is acute myeloid leukemia.