The inventors have determined, contrary to the prior art and experience, how to successfully use triciribine to treat tumors and cancer by one or a combination of (i) administering triciribine only to patients which according to a diagnostic test described below, exhibit enhanced sensitivity to the drug; (ii) use of a described dosage level that minimizes the toxicity of the drug but yet still exhibits efficacy; or (iii) use of a described dosage regimen that minimizes the toxicity of the drug.