HSP90AB1 and neoplasm: iTS cells secrete well-known tumor-suppressing proteins such as p53 and Trail, as well as a group of uncommon tumor suppressors 3, including Hsp90ab1, calreticulin, and peptidylprolyl isomerase B. Most of these tumor suppressors exhibited a dichotomous role, in which they acted oncogenic in the cytoplasm of tumor cells and tumor-suppressive in the extracellular domain.