CS1 (SLAMF7), a pivotal immune receptor, plays a dual role in modulating immune responses in autoimmune diseases and cancer. In autoimmunity, aberrant CS1 signaling contributes to the activation of autoreactive lymphocytes, driving pathologies such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Conversely, in oncology, CS1 serves as a promising immunotherapeutic target, exemplified by the efficacy of the monoclonal antibody Elotuzumab in multiple myeloma. CS1 mediates immune cell functions through intricate signaling pathways, including interactions with EAT-2 and SAP adaptors, which influence cytotoxicity, cytokine production, and immune homeostasis. Beyond cancer and autoimmune diseases, soluble and membrane-bound forms of CS1 are emerging as biomarkers and potential therapeutic targets. Despite significant progress, gaps remain in understanding CS1\u2019s mechanisms, variability in expression, and role in other diseases. This study explores the multifaceted functions of CS1, proposing innovative strategies to leverage its therapeutic potential across diverse pathologies.