The protein encoded by this 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. Alternative splicing of this gene results in multiple transcript variants. Related pseudogenes have been identified on chromosomes 4, 12 and 19. [provided by RefSeq, Apr 2015].