RESUMO
In age groups from 20 to 60 years cell proliferation and differentiation happen in the morphofunctional zone in the electric field excited by 12 pairs of mother and daughter cells, which have turned out at cambial cells division. Thus in daughter cells the Src SH2 domain necessary both for cytoskeleton formation and tyrosinase activization is activated. If the conditions for strengthening of tyrosinase activity are created in organism, despite the high maintenance of cambial cells, the portion of Src participating in the cytoskeleton building can decrease to critical level that will lead to development of a malignant tumor. If action of a stimulating factor is quite strong, proliferation of malignant cells begins at a stage of melanocyte, and a melanoma occurs. If action of factors is long and not strong, more remote descendants of daughter cells proliferate, and a cancer appears. For the purpose of normal differentiation of malignant modified daughter cells, it is necessary to block tyrosinase. Thus all SH2 domains will go on cell cytoskeleton formation.
