The LentiCRISPR P2A-GFP-CALM1 CRISPR/Cas9 construct was outsourced to Shanghai Genechem Co Ltd (Shanghai, China). Lentiviruses carrying green fluorescent protein (GFP) is along with scrambled Lv-sgRNA-control (sgCtrl) and CALM1 sgRNA (Lv-sgCALM1-1, Lv-sgCALM1-2, and Lv-sgCALM1-3). A suitable amount of lentivirus was added to the culture medium of ESCC for transduction, according to the multiplicity of infection (MOI), and the cells were incubated further for 8 h. After 72 h, all fluorescent cells were sorted via flow cytometry and transfection efficiency was evaluated by Western blots and Quantitative real-time polymerase chain reaction (qRT-PCR). The sgRNA target sequences we used were as follows: sgCALM1-1(GACGGACAAGTCAACTATGAA), sgCALM1-2 (CGTGAGGCATTCCGAGTCTTT), sgCALM1-3(AGAAGCTGAATTGCAGGATAT), and sgRNA control (TTCTCCGAACGTGTCACGT).