To test this idea, we sequenced the mtDNA genome in 2 human carcinoma cell lines (HepG2 and MDA-MB-231), identified an SNV in the ND4 gene (12084 C > T) in MDA-MB-231 cells (Fig. 4a) and used the mutant sequence as a PAM to design a Cas12a/crRNA probe. This evidence concerns the gene MT-ND4 and carcinoma.