CD38 and cancer: The effect of loss of CD38 can also be mediated by increasing NAD+ levels, which in turn may enhance the activity of NAD+ consuming enzymes e.g., PARP and sirtuins, that are known to be involved in cancer [35, 36] Additional pathway could be reduction in adenosine (ADO) levels, since the sequential action of CD38, CD203a (also known as PC-1), and 5′-ectonucleotidase CD73 produces adenosine.