Sialic acid-recognizing immunoglobulin-type lectins (Siglecs) are a family of cell surface proteins prominently expressed on immune cells in mammals. Siglec-11 is an example of an inhibitory Siglec. It was the first protein in the brain found to be "human-specific": non-human primates express Siglec-11 in other tissues but not in the central nervous system. UC San Diego School of Medicine professor Ajit Varki discusses the importance of Siglec-11 and the paired receptor Siglec-16, and how they play significant roles in regulating inflammation, and have several uniquely human features including expression in brain. (#37380)