In particular, HD can affect how well the immune system works within brain cells. Science to Suppress Synaptic SnippingAnnexon’s efforts in developing new drugs have focused on a branch of the immune system that becomes overactive in HD. Microglia are guided to synapses by a “tagging” process known as complement, a key part of the immune system. When a drug affects the immune system, there can be a risk of triggering autoimmune-like symptoms. In fact, there’s an entire industry (known as medical communications) focused on the clinical trial publication process, ensuring that scientific findings, especially those involving human participants, are accurately, thoroughly, and thoughtfully reported.