SIGLECs go from homing beacons to next-generation checkpoints

Propelled by growing understanding of their biology, and an expression pattern that goes well beyond T cells, SIGLEC proteins are rising as the next set of checkpoint targets to challenge PD-1. The sugar-binding proteins could prove useful outside of cancer as well.

Two members of the family, CD22 (SIGLEC2) and CD33 (SIGLEC3), have already spawned commercial products as cell-surface markers that direct antibody-based therapies to kill B cell and myeloid cancers, respectively. ...