Experimental scheme to determine whether JNK signaling promotes resistance to chemotherapy. MDA231-LM2 or SUM159-LM1 cells were implanted bilaterally into the fourth mammary fat pads of NSG mice. Treatment with JNKi was initiated at day 5 post implantation and repeated every three days; paclitaxel chemotherapy was started at day 10 post implantation and repeated every five days. 