CCN1 and acute lymphoblastic leukemia: To further identify the effect of Cyr61 on the chemosensitivity of Nalm-6 cells to DNR, exogenous purified Cyr61 protein was used, and the results showed that exogenous Cyr61 increased the IC50 of B-ALL cells to DNR and decreased the DNR-induced apoptosis rate, which could be blocked by the Cyr61 monoclonal antibody (093G9) (Fig. 1d).