In support of this model, they showed that upon AvrRpt2 infection, the sustained MAPK activations were lost in knock-out lines for the genes ALD1 and FMO1 that encode critical steps in the Pip-mediated SAR pathway, as well as in a knock-out line for the gene WRKY33 that codes for a transcription factor positively controlling the expression of ALD1. The gene discussed is ABCD2; the disease is infection.