Recent advances in the real-time imaging of OxtR activities, for example, with a circularly permuted green fluorescent protein binding to OxtR (Ino et al., 2022; Qian et al., 2022), would be useful for delineating the circuit mechanism and spatiotemporal dynamics of the Oxt-mediated suppression of hyperphagic obesity, such as by pinpointing the site of Oxt release. The gene discussed is OXTR; the disease is obesity due to melanocortin 4 receptor deficiency.