Given the task definition and input, reply with output. Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Abstract: We have demonstrated an in vitro secretion of inhibin by human OCCC, not related to subsequent egg cleavage. A putative signal, released by OCCC, that could modulate inhibin secretion by granulosa cells has not been discovered. Inhibin secretion by OCCC has no predictive value concerning the further fertilization and cleavage of the oocytes.
Blastomeres