Can we smell without an olfactory bulb?
This indicates that olfactory function may be present in some subjects even when an OB can not be detected with MRI.
The CTLA-4 gene polymorphism is a non-HLA determinant that predisposes to coeliac disease. Whether it directly contributes to disease susceptibility or represents a marker for a locus in linkage disequilibrium with CTLA-4 needs further investigation.