7BIO is a derivative of indirubin that triggers a rapid cell death process that is distinct from apoptosis and devoid of cytochrome c release or caspase activation. Furthermore, in contrast to other indirubin derivatives, 7BIO has only marginal activity against the classic indirubin targets, cyclin-dependent kinases and GSK3. Instead, 7BIO inhibits FLT3 (IC50 = 0.34 μM) and the dual-specificity tyrosine phosphorylation-regulated kinases, DYRK1A and DYRK2 (IC50s = 1.9 and 1.3 μM, respectively). It also inhibits Aurora B and C kinases with IC50 values of 4.6 and 0.7 μM, respectively.
