BiomaRt 将小鼠的ENTREZID转化为人类的ENTREZID（同源ENTREZID转换）

geneexp.entrez_id = mapIds(x = org.Mm.eg.db,
                           keys = geneLookup,
                           keytype = "ENSEMBLTRANS",
                           column = "ENTREZID")
#先将小鼠的转录本ID转为小鼠的ENTREZID，若是小鼠SYMBOL转ENTREZID，keytype处改成"SYMBOL",其他同理。
library(annotationTools)
library(biomaRt)
human <- useMart('ensembl',dataset = "hsapiens_gene_ensembl")
mouse <- useMart('ensembl',dataset = "mmusculus_gene_ensembl")
m2h.g <- getLDS(attributes = c("entrezgene_id"),filters = "entrezgene_id",
                values = geneexp.entrez_id,mart = mouse,
                attributesL = c("entrezgene_id"),
                martL = human,uniqueRows = T)