Smad4-Shh-Nfic signaling cascade-mediated epithelial-mesenchymal interaction is crucial in regulating tooth root development.

Transforming growth factor beta (TGF-beta)/bone morphogenetic protein (BMP) signaling is crucial for regulating epithelial-mesenchymal interaction during organogenesis, and the canonical Smad pathway-mediated TGF-beta/BMP signaling plays important roles during development and disease. During tooth development, dental epithelial cells, known as Hertwig's epithelial root sheath (HERS), participate in root formation following crown development. However, the functional significance of HERS in regulating root development remains unknown.

Elevated expression of activation induced cytidine deaminase in peripheral blood mononuclear cells precedes AIDS-NHL diagnosis.

Non-Hodgkin's B cell lymphoma (NHL) is a common cancer in HIV infection. Many NHL are thought to result from errors in class switch recombination and/or somatic hypermutation, processes that occur in germinal center B cells, and require the activity of activation induced cytidine deaminase (AID). Since NHL is a common cancer in HIV infection, and expression of AID could contribute to the development of NHL, we hypothesized that AID expression would be elevated in those who went on to develop AIDS-associated NHL (AIDS-NHL).

Infection of human B cells with Epstein-Barr virus results in the expression of somatic hypermutation-inducing molecules and in the accrual of oncogene mutations.

Infection of human B cells with Epstein-Barr virus (EBV) was seen to result in activation-induced cytidine deaminase (AID) and polymerase-eta (pol-eta) gene expression. AID and pol-eta are cellular gene products that play central roles in the DNA-modifying processes involved in immunoglobulin gene class switch recombination and somatic hypermutation. Errors in these processes can result in oncogene mutation/translocation, thereby contributing to lymphomagenesis.