Although we have yet to quantify oxytocin expression in PWS-ICdel mice, a reduction in the population of parvocellular oxytocin neurons has previously been described in humans with PWS (Swaab et al. 1995) and in mice with a specific deletion of Magel2 (Schaller et al. 2010). The gene discussed is MAGEL2; the disease is Prader-Willi syndrome.