In both anti-IgLON5 disease and PSP, abnormal vertical eye movements are found; however, upward gaze palsy can predominate in anti-IgLON5 disease, and mainly downward gaze abnormalities are observed in PSP (González-Ávila et al., 2021). The gene discussed is IGLON5; the disease is supranuclear palsy, progressive, 1.