Afro-textured hair chart below is the most commonly used chart to help determine hair types: Different ethnic groups have observable differences in the structure, density, and growth rate of hair. With regard to structure, all human hair has the same basic chemical composition in terms of keratin protein content. Franbourg "et al." have found that Black hair may differ in the distribution of lipids throughout the hair shaft. Classical afro-textured hair has been found to be not as densely concentrated on the scalp as other follical types. Specifically, the average density of afro-textured hair was found to be approximately 190 hairs per
Retinoblastoma protein of DREAM requires DYRK1A (Ser/Thr kinase) dependant phosphorylation of the MuvB core component, Lin52 at Serine28. This mechanism is crucial for recruitment of p130/p107 to the MuvB core and thus DREAM assembly. The retinoblastoma protein is involved in the growth and development of mammalian hair cells of the cochlea, and appears to be related to the cells' inability to regenerate. Embryonic hair cells require Rb, among other important proteins, to exit the cell-cycle and stop dividing, which allows maturation of the auditory system. Once wild-type mammals have reached adulthood, their cochlear hair cells become incapable of proliferation. In studies where