To test whether GSCs are inherently resistant to cell death caused by stil deficiency, we induced GSC-like properties by overexpressing a constitutively active the Decapentaplegic (Dpp) receptor, Thickveins (Tkv.CA) in germline cells, or the loss of function of bag of marbles (bam), a key differentiation factor (Casanueva & Ferguson, 2004; D. Chen & McKearin, 2003a). This evidence concerns the gene STIL and hyperinsulinemic hypoglycemia, familial, 4.