CID-755673 is a selective small molecule inhibitor of protein kinase D (PKD) (IC₅₀s = 182, 280, 227 nM for PKD1, 2, and 3, respectively). It exhibits higher selectivity for PKD over Akt, polo-like kinase 1, CDK activating kinase, CAMKII and three different PKC isoforms (IC₅₀s range from 15 to > 50 µM). At 25 µM, CID-755673 has been shown to inhibit prostate cancer cell proliferation, cell migration, and invasion.