This gene encodes the major vault protein which is a lung
resistance-related protein. Vaults are multi-subunit structures
that may be involved in nucleo-cytoplasmic transport. This protein
mediates drug resistance, perhaps via a transport process. It is
widely distributed in normal tissues, and overexpressed in
multidrug-resistant cancer cells. The protein overexpression is a
potentially useful marker of clinical drug resistance. This gene
produces two transcripts by using two alternative exon 2 sequences;
however, the open reading frames are the same in both transcripts.
