A calcium (Ca2+) release-activated channel (CRAC) inhibitor, with potential antineoplastic activity. Upon administration, RP4010 binds to and inhibits CRACs, thereby preventing the transport of extracellular Ca2+ into the cell and inhibiting the subsequent activation of Ca2+-mediated signaling and transcription of target genes. CRACs, specialized plasma membrane Ca2+ ion channels composed of the plasma membrane based Orai channels and the endoplasmic reticulum (ER) stromal interaction molecules (STIMs), play key roles in calcium homeostasis and are over-activated in a number of cancer cell types. Aberrant activation of CRACs leads to increased cancer cell proliferation.