Localization of 17βHSD2 protein in human term placentas. Tissue sections of term placentas were immunostained with anti-17βHSD2 (Panels A, C-E) or with pre-adsorbed antibody, as negative control (Panel B). Strong positive signals were observed in terminal villi (TV) (Panels A and C), more precisely in sinusoidal capillaries (Si). 17βHSD2 expression is observed in the paravascular capillary net (PC) as well as in endothelial cells (EC) forming the blood vessel walls of stem villi (SV) (Panels D and E). Some blood vessels are EC positive (+) and others EC negative (-).