Description: The RMT1-4 monoclonal antibody reacts with mouse TIM-1, a member of newly identified T cell immunoglobulin domain, mucin-like domain (TIM) gene family. TIM family of proteins are transmembrane proteins expressed by CD4 T cells. Recent studies demonstrate that the TIM family, particularly TIM-1, plays a critical role in immune responses that regulate the development of atopic diseases. Human TIM-1 is a functional receptor for hepatitis A virus (HAV). In humans, certain polymorphic variants of TIM-1 are strongly associated with protection against atopy, and this association occurs only in individuals who have had past infection with hepatitis A virus (HAV). Activation of T cells through TIM-1 by HAV or by its natural ligand may affect T cell differentiation and the development of Th2-driven allergic inflammatory responses.