CRISPR genome editing has made it easier to create knockout alleles in a variety of species, including the standard laboratory mouse. It’s also made targeted insertions relatively simple in C. elegans and bacteria. But CRISPRing typical mouse models, including creating Cre-dependent conditional alleles, has remained a challenge. Enter Easi-CRISPR: a method that harnesses the power of ssDNA donor molecules for homology directed repair. Using long ssDNA donors, the Gurumurthy and Ohtsuka groups have obtained an average knock-in efficiency of 30-60%. This is much more favorable than previous methods yielding 1-10% knock-in. Read on to learn how you can make CRISPR mouse model generation easi-er!