The c-MYC and Cylclin D1 are reported LEF1 targets and LEF1 activates c-MYC and CyclinD1. Our data showed wild-type LEF1 promotes the transcription and increased mRNA level of c-MYC and Cyclin D1, indicating LEF1 promotes cell proliferation in ALL cells by regulation of gene expression of those targets. The gene discussed is CCND1; the disease is acute lymphoblastic leukemia.