Human-induced pluripotent stem cells (iPSCs) have tremendous potential for regenerative medicine. While there is an ongoing effort to recruit human leukocyte antigen (HLA) homozygous donors for allogeneic transplantation, a significant challenge with this approach is the susceptibility of these cells to host natural killer (NK) cell cytotoxicity. Donor iPSCs that express a single HLA type, such as HLA-C1, may mismatch with NK cells that express two types of killer cell immunoglobulin-like receptors (KIR). This results in NK cell activation and subsequent attack on the donor cells. MaxCyte® enabled the development of HLA heterozygous iPSCs by delivering CRISPR-Cas9 RNPs and single-stranded oligodeoxynucleotides (ssODN) for gene editing. Hotta et al, modified clinical-grade HLA homozygous iPSCs (with two HLA-C alleles) using two ssODN donor templates to generate heterozygous HLA-C1 and HLA-C2 cells. One-step biallelic modification was used to create custom-edited HLA-C iPSCs with allogeneic transplantation potential.