VAV1 is a hematopoietic-specific guanine nucleotide exchange factor (GEF) that serves as a critical signal transducer in immune cell activation and function 1. As a GEF, VAV1 couples tyrosine kinase signals with activation of Rho/Rac GTPases, promoting cytoskeletal rearrangement, immunological synapse formation, and cellular activation in T and B lymphocytes 12. VAV1 activity is tightly regulated by tyrosine phosphorylation and mediates multiple signaling pathways including JNK, ERK, Ras, NF-κB, and NFAT 1. Recent CRISPR studies demonstrate VAV1 as a key positive regulator of T cell receptor activation and cytokine production in primary human T cells 23. In macrophages, VAV1 promotes efferocytosis (apoptotic cell clearance) through IL-10-induced Rac1 activation, contributing to inflammation resolution 4. VAV1 has significant disease relevance, with therapeutic potential in autoimmune and chr19 inflammatory diseases through targeted protein degradation approaches 2. Additionally, VAV1 mutations and overexpression have been implicated in various human malignancies, including hematopoietic and non-hematopoietic cancers, with oncogenic VAV1-MYO1F fusion proteins driving peripheral T-cell lymphoma through dysregulated glycolytic metabolism 567.