Figure 1.

Function of GReX in terms of feature selection and feature aggregation. (A) Feature selection and feature aggregation are two typical steps in the statistical analysis of high-dimensional data. (B) The current practice of TWAS combines feature selection and feature aggregation into a single multiple linear regression model for estimating genetically regulated expression (GReX). (C) Separating these two fundamentally different steps allows a larger combination of methods to be applied to TWAS, providing greater flexibility in practice and potentially increased power. This study quantifies the performance of the four combinations illustrated with colored arrows.