CD38 and B-cell non-Hodgkin lymphoma: Table 5 provides a brief description of the six positive assay results for MCPA and the eight positive assay results for 2,4-D. The level shown is the lowest effective concentration in μM to elicit the response. A change in cell growth kinetics is the most sensitive assay for 2,4-D, while upregulation of CD38 expression is the most sensitive assay result for MCPA. CD38 is a transmembrane glycoprotein highly expressed in B cell lymphoma (http://www.ihop-net.org/UniPub/iHOP/gismo/87033.html) and is known to prevent apoptosis in germinal center B-cells.