The short form of D2 (D2S) and the long form (D2L) are two isoforms that contribute differentially to dopamine signaling in both prefrontal cortex and striatum. The D2 dopamine receptor, short form (D2s) has been shown to stimulate phospholipase D (PLD) activity independent of the activation of phospholipase C (PLC) activity in GH4 derived cells stably transfected with the D2s receptor. Agonist activation of D2s has been shown to mediate the inhibition of growth in the same cell line.