Assignment<FOOTREF>[sup 1] </FOOTREF> of TACSTD1 (alias TROP1, M4S1) to human chromosome 2p21 and refinement of mapping of TACSTD2 (alias TROP2, M1S1) to human chromosome 1p32 by in situ hybridization.

TACSTD1 and TACSTD2 encode cell-surface glycoproteins expressed in epithelial cells. Trops are calcium signal transducers, are over-expressed by human carcinomas and play a role in the control of tumor cell growth. TACSTD2 is responsible for the gelatinous drop-like corneal dystrophy. Although placed within a YAC/BAC/ cosmid contig on 1p, its chromosome location still is undecided at 1p32-&gt;p31 or 1p13-&gt;q12. By fluorescence in situ hybridization of fish, TACSTD2 is assigned to 1p32. The growth-suppressing properties of TACSTD2 and the frequent deletion of 1p32 in human tumors suggest that this gene is a candidate to be a novel oncosuppressor.