Department of Pediatrics, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158, USA.
In this issue of Cancer Cell, Xiao et al. report that PLC-beta3 mutant mice develop myeloprolfierative neoplasms and show that tumor suppressor activity does not require PLC-beta3 catalytic activity. Instead, PLC-beta3 forms a complex with SHP-1 and Stat5 that facilitates Stat5 dephosphorylation. A similar mechanism may be operative in some human leukemias.