While the early findings on a potential role of the Na,K-ATPase could not be further interpreted in terms of a mechanistic model for quite some time, it gained new attention when the Na,K-ATPase, and Tec kinase were identified as factors whose RNAi-mediated down-regulation limits the efficiency of FGF2 secretion ). In follow-up studies, a direct interaction of FGF2 with the cytoplasmic domain of the α1 subunit of the Na,K-ATPase could be demonstrated that was found to be sensitive to ouabain . It was then shown that the Na,K-ATPase acts upstream of PI(4,5)P 2 , accumulating FGF2 at the inner plasma membrane leaflet prior to PI(4,5)P 2 -dependent FGF2 oligomerization and pore formation . Based on these findings, alike Tec kinase , the Na,K-ATPase has been proposed to act as an auxiliary factor of the molecular machinery mediating FGF2 membrane translocation into the extracellular space, representing a landing platform for FGF2 at the inner plasma membrane leaflet ).