虽然我不喜欢DAVID，但很多用户喜欢，所以clusterProfiler也支持了，最近github上又有人要求支持自定义背景。

Dear Guangchuang,

I am using clusterProfiler in Kegg pathway enrichment analysis, it is useful and nice. I am looking for a function which accept background and has ability to deal with Ensembl gene ID.

In a function enrichDAVID it can takes ensembl gene id as an input format, but not allows to enter background. enrichDAVID(gene = gene, idType="ENSEMBL_GENE_ID", annotation="KEGG_PATHWAY", species= "hsa")

Other command enrichKEGG has a background input but only takes entrez gene id, enrichKEGG(gene, organism = "hsa", keyType = "kegg", universe)

I have tried to convert my ensembl gene IDs to entrez gene id, but some ensembl gene IDs represent more than one entrez gene ID. I downloaded KEGG pathway dataset to apply fisher exact test. however, genes are in entrez ID and i am still dont know how to convert.

他提到enrichKEGG不支持ENSEMBL ID，这个可以通过bitr进行ID转换啊，简单得很，只要是有看文档的人都应该知道。

说到enrichDAVID不支持自定义背景，这倒是真的，但这有何难，我随手就支持了。clusterProfiler version>=3.5.3中enrichDAVID也可以使用universe参数了：