TIMP-1 levels are associated with intensity of CD40 and CD38 expression. (A) CD38 expression in BL lines shows a moderate inverse correlation (r = −.70, P₂ = .08) with TIMP-1 production, BL lines expressing higher TIMP-1 levels (<2 ng/mL) are either CD38 negative or show significantly lower CD38(dim) intensity. The X-axis shows secreted TIMP-1 as determined by ELISA. The Y-axis shows CD38 expression as determined by flow cytometry and expressed in MESF as explained in the Materials and Methods. (B) A direct strong correlation (r = .88, P₂= .02) between TIMP-1 production and intensity of CD40 is observed among BL cell lines. The X-axis shows secreted TIMP-1. The Y-axis shows CD40 fluorescence units expressed as MESF as explained in the Materials and Methods. Data represent duplicate MESF determinations of three experiments. ELISA detection of TIMP-1 levels were performed in triplicates for three experiments.