CD38 and neoplasm: Through use of different in vivo systems and CD38-directed AttenukineTM surrogates, a deeper understanding of the potential mechanistic effects of a CD38-directed AttenukineTM was realized, with evidence of tumor growth inhibition, demonstrated through direct effects of IFNα on tumor cells as well as by modulating an anti-tumor immune response, in the absence of any adverse effects based on gross observation and body weight change alone.