"Crowd-control" by RNA: a pervasive theme in biology.

As we continue to find new regulatory roles for RNAs, a theme is emerging in which regulation may not be mediated through the actions of a specific RNA, as one typically thinks of a regulator and target, but rather through the collective nature of many RNAs, each contributing a small degree of the regulatory load. This mechanism has been termed "crowd-control" and may apply broadly to miRNAs and to RNAs that bind and regulate protein activity. This provides an alternative way of thinking about how RNAs can act as biological regulators and has repercussions, both for the understanding of biological systems, and for the interpretation of results in which individual members of the "crowd" can replicate the effects of the crowd when overexpressed, but are not individually significant biological regulators.