Multi-fiber, fiber optic cable assemblies may be configured so that the terminal ends of the cables have pre-assembled back-post assemblies that include pre-assembled ferrules, such as MPO ferrules that meet the requisite tolerances needed for fiber optic transmissions. Verification is performed at a mobile station which receives transmit signals sent by the base transceiver station. The invention provides methods used in the design and identification of ligands of Site II and of modulators of nuclear hormone receptors.