41 Mouse cryptdins are processed into their active form by matrix metalloproteinase 7 (MMP7) during granulogenesis.6,33 Indeed, mice lacking MMP7 cannot process the precursors of pro-cryptdin, leading to a deficiency of mature cryptdins, thus impairing their ability to scavenge infections and regulate immune homeostasis.6 In mouse and human PCs, mature α-defensin is oxidized to prevent internal digestion.115. This evidence concerns the gene MMP7 and infection.