Disclosed is a compound of formula I e.g. (N-(2-cyclohexyl-5,6-dimethylpyrimiidin-4-yl)-5-fluoro-1H-pyrazolo[3,4-b]pyridin-3-amine or a pharmaceutically acceptable salt thereof, wherein Ht, ring D, Z1, RX, RY is defined in the specification for treating or lessening the severity of a disease or condition selected from diabetes, osteoporosis, Alzheimers disease, Huntingtons disease, Parkinsons disease, AIDS-associated dementia, bipolar disorder, amyotrophic lateral sclerosis (ALS, Lou Gehrigs disease), multiple sclerosis (MS), schizophrenia, leukocytopenia, stroke, and rheumatoid arthritis.
