Hybridomas developed from mouse spleen cells fused to a myeloma cell line can be developed as a source for the cDNA encoding the CD19 specific antibody. The cDNA is sequenced and the sequence encoding the variable heavy and variable light chains of these antibodies are cloned together using a small peptide linker. This resulting sequence encodes the scFv. This can be cloned into a transgene, encoding what will become the endodomain of the CAR. Varying arrangements of subunits serve as the endodomain, but they generally consist of the hinge region that attaches to the scFv, a transmembrane region, the intracellular region of a costimulatory molecule such as CD28, and the intracellular domain of CD3-zeta containing ITAM repeats. Other sequences frequently included are: 4-1bb and OX40. The final transgene sequence, containing the scFv and endodomain sequences is then inserted into immune effector cells that are obtained from the person and expanded in vitro. In trials these have been a type of T-cell capable of cytotoxicity.Inserting the DNA into the effector cell can be accomplished by several methods. Most commonly, this is done using a lentivirus that  encodes the transgene. Pseudotyped, self-inactivating lentiviruses are an effective method for the stable insertion of a desired transgene into the target cell. Other methods include electroporation and transfection, but these are limited in their efficacy as transgene expression diminishes over  time. The gene-modified effector cells are then transplanted back into the person.
Fibrofolliculomas are 2 to 4 mm in diameter, dome-shaped, yellowish or skin-colored papules usually located on the head, neck, and upper trunk. They are characteristically seen in Birt–Hogg–Dubé syndrome. : 674

See also
List of cutaneous conditions
List of cutaneous neoplasms associated with systemic syndromes
Trichodiscoma


== References ==