 Lyn, the type of kinase that was the first to be discovered in the nuclear matrix, is part of Src family of tyrosine kinases, which can be contained in the nucleus of differentiating, calcium-provoked kertinocytes.Lyn, in the nuclear matrix, among the nuclear envelope and the “fibrous web” that physically stabilizes DNA, was found functioning in association with the matrix.Also, it appeared to be conditional to cell cycle.