Our results indicate that acute postpartum steroid sulfatase deficiency results in abnormal maternal behaviour (at least in mice), and begin to define a brain pathway that may feasibly be disturbed in women diagnosed with PP i.e. signalling from the extracellular matrix to the cytoplasm via Ccn proteins, transmembrane proteins such as integrins and Notch, and intracellular molecules. Here, STS is linked to hyperinsulinemic hypoglycemia, familial, 4.