In human endometrial stromal cells and rat neuroblastoma cells, cAMP stimulates STC‐1 expression.21, 22 However, in rat Sertoli and Leydig cells the opposite effect was observed.23 It has previously been reported that elevated intracellular cAMP‐induced cell fusion and differentiation in BeWo cells.24 In this study, 8Br‐cAMP alone had no effect on the secretion of STC‐1 by BeWo cells cultured in atmospheric oxygen suggesting that differentiation of BeWo cells alone was insufficient for secretion. This evidence concerns the gene STC1 and neuroblastoma.