For example, the SDM was successfully applied to PF04942847, a small-molecule inhibitor to heat shock protein 90 (HSP90), given a temporal delay between plasma concentrations of PF04942847 and the inhibition of its downstream protein, protein kinase B (PKB/AKT) in a human breast cancer MDA-MB-231 xenograft tumor mouse model [98]. The gene discussed is AKT1; the disease is breast cancer.