Although, due to technical limitations, the overall efficiency of this knock-in application remains much lower as compared to the generation of knockout mutations, the generation of such patient-specific genetic avatars has been accomplished in TDP43/ALS (Armstrong et al., 2016), in FBN1 in various heritable connective tissue disorders (HCTD) (Yin et al., 2021), RPS14 in myelodysplastic syndrome (MDS) (Ear et al., 2016). The gene discussed is TARDBP; the disease is myelodysplastic syndrome.