In addition, in 2008, reports appeared showing that the some of the dopamine cells within the hfVM grafts had acquired the alpha synuclein pathology of PD.[32, 33] The reason for this was not clear, and is still not fully known, but was thought to relate to pathological alpha synuclein spreading from the host PD brain into the grafted cells, where it then templated pathology using the grafted cells own endogenous alpha synuclein. This evidence concerns the gene SNCA and Parkinson disease.