Although there are always concerns about mosaicism when editing embryos, we tried to minimize mosaicism by using RNP complex, i.e., Cas9 protein and guide RNA complex according to previous report [7, 21].Three targeted loci were selected, that is, MSTN for productivity, PRNP for disease resistance, and BLG for allergy free milk. Here, RNPC3 is linked to allergic disease.