show Abstracthide AbstractMost tumors of the upper gastrointestinal tract are known to depend on an excessive expression of Shh. It was recently discovered that this Shh does not signal on the tumor cells, but rather the stromal cells that in turn produce an unknown set of reciprocal signals that act as growth- or survival cues for the tumor cells. This sequencing effort aims to identify the reciprocal signals. Overall design: Mouse fibroblasts and Shh-expressing human pancreatic adenocarcinoma cells were either grown alone, or in a non-adherent coculture system. To be able to assess the effect of Shh on fibroblast gene expression (being the reciprocal signal), 5E1 blocking antibody was added to the cells and after 5 days, RNA was isolated. n=1