A compound having the general structure of Formula (I): ##STR00001## or a pharmaceutically acceptable salt, solvate, or ester thereof, are useful in treating diseases, disorders, or conditions such as immunodeficiencies, cancers, cardiovascular diseases, endocrine disorders, Parkinson's disease, metabolic diseases, tumorigenesis, Alzheimer's disease, heart disease, diabetes, neurodegeneration, inflammation, kidney disease, atherosclerosis and airway disease.