say           $transcripts{$transcript_ip}{$transcript_id};                           # gives me the hash reference of the lowest (3rd deep hash)
say        %{ $transcripts{$transcript_ip}{$transcript_id} };                         # gives me that entire hash (key value pairs)
say        %{ $transcripts{$transcript_ip}{$transcript_id} }{@transcripts_columns};   # gives me my desired slice of that hash (key value pairs)
say keys { %{ $transcripts{$transcript_ip}{$transcript_id} }{@transcripts_columns} }; # gives me my desired slice of that hash (keys only)
say        @{ $transcripts{$transcript_ip}{$transcript_id} }{@transcripts_columns};   # gives me my desired slice of that hash (values only)