Immune Cell Signature Retrieval and Single-Cell Scoring R package ImmuneSigR version 0.1.0 Provides a literature-derived database of immune cell markers formatted as Gene Matrix Transposed (GMT) files. Users can search immune cell signatures, retrieve marker lists, export GMT files, create custom marker sets, and score gene-by-cell expression matrices with dependency-free rank-based or mean-expression methods. Cell subpopulations are distinguished by their source PMIDs. For the core curation of the lung cell atlas, see Travaglini et al. (2020) <doi:10.1038/s41586-020-2922-4>. For the pan-cancer B cell signatures, see Fitzsimons et al. (2024) <doi:10.1016/j.ccell.2024.09.011>. Software Suggests: knitr, rmarkdown Yingyan Liang <liangyingyan0625@163.com> Comprehensive R Archive Network (CRAN) Yingyan Liang [aut, cre], Peng Luo [aut] GPL-3 2026-05-19 application/tgz https://CRAN.R-project.org/package=ImmuneSigR doi:10.32614/CRAN.package.ImmuneSigR