To cite package ‘genefu’ in publications use:

  Deena M.A. Gendoo, Natchar Ratanasirigulchai, Markus S. Schroeder,
  Laia Pare, Joel S Parker, Aleix Prat, Benjamin Haibe-Kains (2021).
  _genefu: Computation of Gene Expression-Based Signatures in Breast
  Cancer_. R package version 2.37.0,
  <https://bioconductor.org/packages/genefu>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {genefu: Computation of Gene Expression-Based Signatures in Breast Cancer},
    author = {{Deena M.A. Gendoo} and {Natchar Ratanasirigulchai} and {Markus S. Schroeder} and {Laia Pare} and {Joel S Parker} and {Aleix Prat} and {Benjamin Haibe-Kains}},
    year = {2021},
    note = {R package version 2.37.0},
    url = {https://bioconductor.org/packages/genefu},
  }