Iron deficiency altered methylation at the genes regulating ephrin B signaling/ephrin receptor signaling (data not shown), including increased methylation at Ephb1, Itsn1, Prkar1b, and Srgap2, and decreased methylation at Arhgef15, Mknk1, and Slit3 loci (Table 1). The gene discussed is PRKAR1B; the disease is nutritional disorder.