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A nucleolar detention center (DC) is a region of the cell in which certain proteins are temporarily detained in periods of cellular stress. DCs are absent from cells under normal culture conditions, but form in response to specific environmental triggers, such as low extracellular pH or high temperature, when long noncoding RNAs are induced from regions of intergenic DNA. The detention of numerous proteins in DCs is believed to reduce metabolic activity and promote survival under unfavorable conditions. DCs form at the center of nucleoli and therefore disrupt the normal organization of these organelles. The structural remodeling that ensues leaves nucleoli unable to sustain their primary function, ribosomal biogenesis. Therefore, the formation of DCs is thought to convert nucleoli from “ribosome factories” to “prisons for proteins”.