. Author manuscript; available in PMC: 2018 Sep 18.
Published in final edited form as: Cytokine Growth Factor Rev. 2016 Aug 25;31:61–71. doi: 10.1016/j.cytogfr.2016.08.002
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).