Group 2 consist of proteins containing only a START domain; group 3 proteins are capable of binding different ligands, such as phosphatidyl choline (STARD2/PCTP) and ceramides (STARD11); group 4 proteins (DLC, or deleted in cancerous liver cells) are frequently de-regulated in cancer and contain Rho-GTPase activating domains; group 5 proteins contain two thioesterase domains; and group 6 consists of only STARD9, a 4614-residue protein with unknown function, that contains a kinesin motor domain at its N-terminus. The gene discussed is PCTP; the disease is cancer.