PPBSF is a complex of IL7 and HGFbeta Authored: Ray, KP, 2010-05-17 Edited: Jupe, S, 2011-05-06 Pubmed11564764 Pubmed12184921 Reactome Database ID Release 431266684 Reactome, http://www.reactome.org ReactomeREACT_116110 Reviewed: Puck, J, 2011-11-03 The pre-pro-B cell growth-stimulating factor (PPBSF) is a self-assembling complex of IL7 and a variant beta-chain of hepatocyte growth factor (HGFbeta) (Lai & Goldschneider 2001). This 55 kDa heterodimer, unlike monomeric IL7, selectively stimulates proliferation and differentiation of pre-pro-B cells in a long-term bone marrow culture system and up-regulates IL7R alpha chain expression on pre-pro-B cell surface. It has been postulated that PPBSF is the active form of IL7 that normally induces IL7R-lo pre-pro-B cells to proliferate and differentiate into IL7R-hi pro-B cells, which then proliferate and differentiate into pre-B-cells on stimulation with monomeric IL7 (Wei et al. 2002). PPBSF