The targeting vector contains a CMV enhancer/chicken beta-actin core promoter (CAGGS), a loxP-STOP(6xSV40 polyA)-loxP cassette (LSL), an enhanced Acidaminococcus cas12a variant, including several substitutions (E174R/N282A/S542R/K548R; enAsCas12a),a nucleoplasmin nuclear localization signal (NLS), a 3xHA epitope sequence, an SV40 NLS and a rabbit β-globin polyadenylation signal (RBG pA). (J:101977)