I have finished makeTranscriptDbFromGFF step, but I am not sure whether it fished successfully? could you help me check? -- output of sessionInfo(): > txdb <- makeTranscriptDbFromGFF("D:/R-package/RtmpE7FyTD/downloaded_ packages/tmp.out",format="gff3",exonRankAttributeName=NA,dataSource="g ff file for test", species="test") extracting transcript information Extracting gene IDs extracting transcript information Processing splicing information for gff3 file. Deducing exon rank from relative coordinates provided Prepare the 'metadata' data frame ... metadata: OK Now generating chrominfo from available sequence names. No chromosome length information is available. Warning messages: 1: In as.data.frame(data, stringsAsFactors = FALSE) : Arguments in '...' ignored 2: In .deduceExonRankings(exs, format = "gff") : Infering Exon Rankings. If this is not what you expected, then please be sure that you have provided a valid attribute for exonRankAttributeName 3: In matchCircularity(chroms, circ_seqs) : None of the strings in your circ_seqs argument match your seqnames. -- Sent via the guest posting facility at bioconductor.org.