Bruton's tyrosine kinase (BTK), encoded by the BTK gene, is a cytoplasmic protein critical in B cell development. Mutations in the BTK gene cause X-linked agammaglobulinemia (XLA), a primary immunodeficiency with characteristically low or absent B cells and antibodies. This report describes a five
The naturally occurring autofluorescence of cells and tissues is based on biomolecules containing intrinsic fluorophores, such as porphyrins, the amino acids tryptophan and tyrosine, and the coenzymes NADH, NADPH, and flavins. Coenzymes fluoresce in the blue/green spectral region (fluorecence