I have 3224 Ensembl id's as rownames in a dataframe "G". To convert Ensembl ids into Genesymbols I used biomart like following.
library('biomaRt') mart <- useDataset("hsapiens_gene_ensembl", useMart("ensembl")) genes <- rownames(G) G <-G[,-6] G_list <- getBM(filters= "ensembl_gene_id", attributes= c("ensembl_gene_id" "hgnc_symbol"),values=genes,mart= mart)
Now in G_list I can see only 3200 ensembl ids showing Genesymbols / No Gene_symbols. Why the other 24 ensembl ids are not seen in G_list? If there are no gene_symbol for those 24 ensembl ids it should atleast show "-"
what is the problem here?