For example, a study examining the effectiveness of the CPP HA2-ApoE (130-150) showed promising results in increasing the levels of functional SMN2 mRNA in patient-derived fibroblasts and in the SMN2 transgenic mouse model of spinal muscular atrophy (SMA) when administered via tail vein injection at a dose of 8 mg/kg (Dastpeyman et al., 2021). The gene discussed is APOE; the disease is proximal spinal muscular atrophy.