The characterization of several furanoheliangolide-type STLs that were initially found to inhibit MYB activity [29] confirmed and substantially extends our previous work on the STL helenalin acetate [32, 33] in demonstrating a key role of C/EBPβ as a pro-leukemogenic MYB-cooperating factor in AML cells. This evidence concerns the gene CEBPB and acute myeloid leukemia.