Tabix indexes a TAB-delimited genome position file in.tab.bgz and
creates an index file in.tab.bgz.tbi when region is absent from the
command-line. The input data file must be position sorted and
compressed by bgzip which has a gzip like interface. After indexing,
tabix is able to quickly retrieve data lines overlapping regions
specified in the format "chr:beginPos-endPos". Fast data retrieval
also works over network if URI is given as a file name and in this
case the index file will be downloaded if it is not present locally.