HIF-1? protein can work directly to stop new cells from forming
 

A protein known for turning on genes to help cells survive low-oxygen conditions also slows down the copying of new DNA strands, thus shutting down the growth of new cells, Johns Hopkins researchers report. Their discovery has wide-ranging implications, they say, given the importance of this copying - known as DNA replication - and new cell growth to many of the body's functions and in such diseases as cancer.

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