MRGPRX2 and astrocytoma (excluding glioblastoma): To this end, we used recombinant 1321N1 astrocytoma cells that stably expressed MRGPRB2, employing Ca2+ assays, and CST-14 as MRGPRX2/MRGPRB2 agonist (EC80 value of 2000 nM).31 In fact, the compounds inhibited MRGPRB2 as well with pKi values that showed a significant correlation with those determined for the human receptor (correlation coefficient (r) of 0.791) (Fig. 7a).