Sequence clustering

The sequences can be either of genomic, "transcriptomic" (ESTs) or protein origin.

For proteins, homologous sequences are typically grouped into families.

For EST data, clustering is important to group sequences originating from the same gene before the ESTs are assembled to reconstruct the original mRNA.

The similarity score is often based on sequence alignment.

Sequence clusters are often synonymous with (but not identical to) protein families.