Task: Named Entity Recognition
Input (English):  Stimulation of T lymphocytes results in a rapid increase in intracellular calcium concentration ( [ Ca2 + ] i ) that parallels the activation of Ca2 + - calmodulin - dependent protein kinase IV ( CaMKIV ) , a nuclear enzyme that can phosphorylate and activate the cyclic adenosine monophosphate ( cAMP ) response element - binding protein ( CREB ) .
Output (English): nuclear enzyme