Nextdoor is the private social network for your neighborhood. On Nextdoor, neighbors create private groups for their neighborhoods where they can ask questions, get to know one another, and exchange local advice and recommendations.
Up-regulation is a process that occurs within a cell triggered by a signal (originating internal or external to the cell), which results in increased expression of one or more genes and as a result the protein(s) encoded by those genes.
Gene expression occurs because of certain signals in your body, both inside and outside of your cells. Cell differentiation occurs during multiple stages of development. During cell differentiation, the cell size and shape changes dramatically, as does its ability to respond to signaling molecules.