Salivary gland. The sequence shown is that from strain Oregon-R. The number of the 7 residues repeat vary between strains: strain Oregon-R(2/10) has 11 more copies, strain Karsnas has 8 more copies of the repeat, strain Samarkand-pk1 has 1 less copy and strain Samarkand-pSW9 and strain Berkeley have 2 less copies.