In the Royal College of Surgeons rats in which the exon 2 of Mertk gene is deleted leading to retinal degeneration, the HITI approach allowed the successful insertion of exon 2 into intron 1, resulting in partial restoration of MERTK expression, retinal morphology and function (Suzuki et al., 2016). The gene discussed is MERTK; the disease is retinal degeneration.