Analysis of Omics Data in Observational Studies R package epiomics version 1.2.0 A collection of fast and flexible functions for analyzing omics data in observational studies. Multiple different approaches for integrating multiple environmental/genetic factors, omics data, and/or phenotype data are implemented. This includes functions for performing omics wide association studies with one or more variables of interest as the exposure or outcome; a function for performing a meet in the middle analysis for linking exposures, omics, and outcomes (as described by Chadeau-Hyam et al., (2010) <doi:10.3109/1354750X.2010.533285>); and a function for performing a mixtures analysis across all omics features using quantile-based g-Computation (as described by Keil et al., (2019) <doi:10.1289/EHP5838>). Software Depends: R (>= 4.1.0) Imports: data.table, ggplot2, ggrepel, qgcomp, stats, survival Suggests: testthat (>= 3.0.0) Jesse Goodrich <jagoodri@usc.edu> Comprehensive R Archive Network (CRAN) Jesse Goodrich [aut, cre] (ORCID: <https://orcid.org/0000-0001-6615-0472>) GPL (>= 3) 2025-02-14 application/tgz https://CRAN.R-project.org/package=epiomics doi:10.32614/CRAN.package.epiomics