Hepatitis A virus cellular receptor 1 is also known as HAVCR1, HAVCR, KIM1, TIM, TIM1, TIMD1, is widely expressed with highest levels in kidney and testis. The protein encoded by HAVCR1 gene is a membrane receptor for both human hepatitis A virus (HHAV) and TIMD4. The encoded protein may be involved in the moderation of asthma and allergic diseases. The reference genome represents an allele that retains a MTTVP amino acid segment that confers protection against atopy in HHAV seropositive individuals. Three transcript variants encoding the same protein have been found for this gene. HAVCR1 may play a role in T-helper cell development, the regulation of asthma and allergic diseases and in kidney injury and repair. In case of human hepatitis A virus (HHAV) infection, functions as a cell-surface receptor for the virus.