Transcription activator-like effector
TAL (transcription activator-like) effectors (often referred to as TALEs, but not to be confused with the three amino acid loop extension homeobox class of proteins) are proteins secreted by some β- and γ-proteobacteria. Most of these are Xanthomonads.
Source: Wikipedia — Transcription activator-like effector (CC BY-SA 4.0)