Effects of the LPA1/3 antagonist Ki16425 (a) alone and co-treatment with Ki16425 and the GPR55 antagonist CID16020046 (b) on gintonin (0.1 μg/mL)-mediated [Ca2+]i transients in PC-3 cells. Analyses of calcium signal localization were performed, as described in Figure 5. Left panel (a,b): representative pictures of [Ca2+]i levels in PC-3 cells in the absence or presence of Ki16425 (10 μM) or CID16020046 (10 μM) plus Ki16425. Upper right panel: representative peaks of [Ca2+]i transients in the absence or presence of Ki16425 or CID16020046 (10 μM) plus Ki16425. Lower right panel (a,b): histograms of the effects of Ki16425 or CID16020046 (10 μM) plus Ki16425 on gintonin (0.1 μg/mL)-mediated [Ca2+]i transients. Data were obtained from 40–50 different cells in three independent experiments. Data represent means ± SD. **** p < 0.0001, compared to the presence of inhibitor (Ki16425, Ki, or CID16020046 plus Ki). GT, gintonin.