H1-0 and melanoma: B16 murine melanoma cells treated with sodium butyrate, for example, were found to cease to proliferate rapidly and to start to synthesize melanin; this process was reversible, and if butyrate was removed from the culture medium, the cells started again proliferating rapidly; when starting to differentiate, the cells overexpressed H1.0 mRNA, even if the cells were still proliferating; the level of H1.0 mRNA decreased then very rapidly after butyrate withdrawal [117].