Count normalization requires Ensembl Ids to be unique. In rare cases, there are more than one HGNC symbol per gene Id. This function collapses the duplicate entries into a single entry by appending the HGNC symbols in a comma separated list.
collapse_duplicate_hgnc_symbol(biomart_results)Output of "sageseqr::get_biomart()". Gene Ids are
stored as rownames.