BCL9 and neoplasm: Upon stimulation of upstream activators and the helping of some transcription factors such as BCL9, β-catenin protein translocates to the nucleus from the cytoplasm, binds to the promoter of TCF/LEF, and activates the transcription of its target genes such as c-Myc, cyclinD1, and MMP7, leading to tumor initiation and development [18, 19, 30, 31].