SSDH is also important for the GABA shunt, an alternative to the TCA cycle, but in this case, SSDH deficiency results in an increase in the inhibitory transmitter GABA.[24] Metabolic therapies for AD have recently been suggested, but SSDH represents a novel target in the TCA cycle not previously proposed, as discussed further below. The gene discussed is ALDH5A1; the disease is Alzheimer disease.