Surprisingly, placental gene expression for IRS1 and IGFR1 was not affected by obesity or GDM, findings that differ with those described by Jansson et al (41) in a cohort of Swedish women, in which placental activation of mTOR was accompanied by enhanced insulin/IGF 1 signaling with raised BMI. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.