The stitcher CA transgenic fly line used in Tsarouhas et al., 2019, Nat. Commun. 10(1): 2193 <up>FBrf0242366</up> contains a constitutively active form of Stit ('lambdaStit') expressed under the control of UAS regulatory sequences.
lambdaStit was first described in Wang et al., 2009, Nat. Cell Biol. 11(7): 890--895 where it was expressed in S2 cells; the Stit extracellular region has been replaced by the lambda cI repressor dimerization domain to force ligand-independent dimerization, resulting in a constitutively active protein.