Such SST specificities were also observed in pituitary tumor cells, where, in contrast to SST2, SST1 fails to stimulate phosphoinositide-specific phospholipase C (PLC) activity or PLC-dependent release of Ca2+ from intracellular stores (Chen et al., 1997), but transduces inhibition of phospholipase A2 activity and arachidonic acid release, similar to SST2 (Cervia et al., 2002). Here, SSTR1 is linked to pituitary tumor.