CDK7 and leukemia: Interestingly, combination therapy with BRD4 inhibitors and CDK7 inhibitors overcomes resistance to BRD4 inhibitor therapy in leukemia cells and mouse models of leukemia [44]; and nanoparticle-mediated delivery of JQ1 and THZ1, compared with free drug formulation, considerably reduces cytotoxicity to liver cells but synergistically suppresses tumor progression in a mouse model of drug-resistant pancreatic ductal adenocarcinoma [42].