MMP2 and hypersensitivity pneumonitis: In the MMP1 gene, the rs7125062 was associated in the comparations HPAbs+ and HP vs. HC group; while rs11646643 in the MMP2 gene is associated with the risk of disease and the decline of the lung function in HP; i.e., we can able to identify genetic differences among HPAbs+ and HP patients without autoantibodies.