Potent and highly specific cell permeable protein kinase C (PKC) inhibitor. The inhibition of PKC is light-dependent. PKA, PKG, DAG kinase, phospholipase D1 and D2, myosin light chain kinase and c-Src inhibitor. Anticancer compound. Inhibits cell proliferation and strongly induces apoptosis in vitro. Inducer of endoplasmic reticulum ER-stress. Shown to directly and potently block L-type Ca channels. Calphostin C specifically inhibits contraction-stimulated glucose transport but not insulin-stimulated glucose transport in skeletal muscle. Wnt/beta-catenin/lef-1 signaling inhibitor. beta-catenin/TCF antagonist. Inhibits Wnt-activated genes in a dose-dependent fashion