Board Thread:Theories and Speculation/@comment-24267641-20150816132215/@comment-3279282-20150816172149

Yin Release and Yang Release are no chakra natures, if you mean that. They're applied during the process of creating the chakra itself, whereas chakra natures are applied afterwards.

As for the topic, it could be that Yin Release is used to artificially create the cells that are used to replace the destroyed cells.