The skin surrounding postburn keloid cicatrices showed high proliferative and functional activity of the cell elements comprising the vessel wall or located near it. Keloid cicatrices differed from the surrounding skin by the lower content and lower activity of cell elements in general and mast cells in particular. Here too, however, the highest intensity of biosynthesis was found in blood vessels and perivascular zones. Both in the keloid and the skin surrounding it, more frequently distally from the blood vessels, there was a large number of cells in which RNA and protein synthesis could not be detected autoradiographically, and destructive and necrotic lesions were observed. Not infrequently such cells were in immediate proximity to biosynthetically active cells.