Fig. 2.

Architectures of homodimeric heavy‐chain antibodies (bottom left) with the Ag‐binding single‐domain VHH enlarged on top and classical heterotetrameric antibodies (bottom right) with the Ag‐binding variable fragments (comprising VH and VL domains) enlarged on top. Adapted from Muyldermans (2021, ref 33). (Permission under Creative Commons Attribution license) (https://doi.org/10.1111/febs.15515).

Abbreviations: VHH, variable heavy chain-only antibodies; CH, constant region of heavy chain; VL, variable region of light chain; CDR, complementarity-determining region.