ALB and neoplasm: To determine whether the effect of Poly-SNO-HSA on resistant tumor cells was mediated by cGMP signaling, we used the soluble guanylate cyclase inhibitor 1-H-(1,2,4)oxadiazolo-(4,3-a)quinoxalin-1-one (ODQ) and the nonhydrolyzable cGMP analogue 8-Br-cGMP.