Both the calcium binding protein S100A4/Mts1 and its endogenous receptor (receptor for advanced glycosylation end products; RAGE) have been implicated in the development of sex hormone-dependent formation of the cortical bone (Erlandsson et al., 2013) and pulmonary arterial hypertension (Dempsie et al., 2011). Here, S100A4 is linked to pulmonary arterial hypertension.