SCIMP (SLP adaptor and CSK interacting membrane protein) is a palmitoylated transmembrane adapter protein that functions as a scaffold for immune signaling 1. In B cells and antigen-presenting cells, SCIMP localizes to tetraspanin-enriched microdomains and immunological synapses, where it associates with Lyn kinase and becomes phosphorylated upon MHC-II stimulation, subsequently binding SLP65 adaptor protein to initiate downstream calcium and ERK signaling cascades 2. SCIMP also serves as a proximal adapter for TLR signaling (TLR1, TLR2, TLR3, TLR4, TLR7) through atypical TIR-non-TIR interactions, selectively promoting pro-inflammatory IL-6 and IL-12B production in macrophages 3. Recently, exosomal SCIMP secreted by macrophages was shown to enhance neutrophil recruitment via FPR1/2 signaling, protecting against acute lung injury in pneumonia 4. Clinically, SCIMP has emerged as relevant to multiple diseases: reduced SCIMP levels correlate with postmenopausal osteoporosis progression through Akt-dependent osteoclast dysfunction 5, and increased immune cell SCIMP expression associates with elevated Alzheimer's disease risk 6. These findings establish SCIMP as a multifunctional immune signaling node with therapeutic implications in infectious, metabolic, and neurodegenerative diseases.