It is not rare that an unfortunate biology paper has to be retracted. Such is the case for a 2011 Journal of Neuroscience paper (http://www.ncbi.nlm.nih.gov/pubmed/21900561) which was retracted in 2012.
But I find it extremely disturbing that it continues to be cited for another 14 times (> 2 folds of the journal's IF) since 2013-2015, by peer-review journals & book. I checked some of the research articles, and none of them highlight the retraction status of this paper. Journals including Pain, Molecular pain, Encyclopedia of Pain from Springer.
DO NOT KNOW HOW & WHY! Not sure if it will gain citations in the coming 2016.
It makes me angry also. Why they do not even bother to check if the research they cite is valid or not?