BLASTn:   nucleotides sequences compares against nucleotide databases.
BLASTp:   protein sequences compares against protein databases.
BLASTx:   six-frame translations of a nucleotide query sequence compare against
                 a protein databases.
tBLASTx:  six-frame translations of a nucleotide query sequence compare against
                 six-frame translations of a nucleotide sequence database.
tBLASTn:  A protein query sequence compares against
                  six-frame translations of a nucleotide sequence database.