Provided herein are methods and compositions related to a retinoid receptor-selective pathway. As described herein, this pathway can be targeted to manipulate a tumor microenvironment. For example, the methods and compositions described herein can be used to induce apoptosis in a cancer cell. Further, the compositions described herein, including Sulindac and analogs thereof, can be used to target this pathway for the treatment or prevention of cancer in human patients.

The invention provides compounds of formulae (I), (II), (III), and (IV): and salts thereof, as well as pharmaceutical compositions comprising such compounds. The compounds are useful for treating cancers and Alzheimer's disease. ##STR00001##

The invention provides compounds of formulae (I), (II), (III), and (IV): and salts thereof, as well as pharmaceutical compositions comprising such compounds. The compounds are useful for treating cancers and Alzheimer's disease. ##STR00001##

Polymorphs of co-crystals of itanapraced and nicotinamide and pharmaceutical compositions and dosage forms containing the polymorphs are described. Methods of synthesizing the polymorphs and uses of polymorphs are also described.