A cell-permeable phenoxypyrimidin-cyclopropanecarboxamide compound that effectively stimulates the growth of primary beta cells in cultured primary rat and human islets in vitro (ECmax in 4 d = 200 and 400nM, respectively) and in the murine type 1 diabetes (T1D) model RIP-DTA in vivo (170% of control pancreas Ki-67-positive beta cells in 1 wk; 5mg/kg i.p. q.o.d.) by interacting with IKKε and EBP1/PA2G4/Erb3 binding protein-1 and blocking the known suppressor function of EBP1 toward E2F-mediated transcription. Likewise, dual inhibition of EBP1 (with shRNA) and IKK (1uM) is shown to fully recapitulate the proliferating effect of WS6 in R7T1 cells.