WEE1 and myeloid leukemia: As previously described, triterpenoids were shown to inhibit various protein kinases: e.g., ursolic acid has been reported to inhibit tyrosine kinase activity [38,39], and plant-derived pentacyclic triterpenoid gypsogenin and derivatives were reported by Ciftci et al. to show activity against myelogenous leukemia by virtue of their inhibition of ABL1 kinase [30].