CCN1 and neoplasm: Indeed, flow cytometry with anti-CD4 antibodies revealed that, whereas few T cells penetrated the tumors embedded within a wild-type tumor stroma, there was a trend toward more CD4+ T cells (P = 0.057) being observable in CCN1-deficient stroma (1.20% ± 0.45% vs. 12.07% ± 4.06%, CCN1f/f vs. CCN1−/−, Fig. 7A).