This is an abbreviation for “Tissue-Wide.” We have historically created a Cross-Tissue model, which is a measure of the expression common across all tissues, and Tissue-Specific models (TS), which is modeled as an orthogonal component to the shared cross tissue component. Details can be found here(http://dx.doi.org/10.1101/043653). While these models are not available at the moment, they are in our pipeline.