Abstract: Boron containing compounds are targeted to hormonally responsive cells by contacting the cells with a conjugate of a boron containing moiety conjugated to a ligand having binding specificity for an intracellular receptor of the cell. The conjugates are useful for imaging or killing hormonally responsive cells, such as hormonally responsive tumor cells. For target cell killing, the cells are contacted with a .sup.10 B containing moiety conjugated to a ligand having binding specificity for an intracellular hormone receptor of the cells. The .sup.10 B containing moiety becomes associated with the hormone receptor of the cells, which may then be irradiated with neutrons to kill the cells by boron neutron capture. For target cell imaging, the cells are contacted with a .sup.