Serine protease inhibitor Kazal-type 7(SPINK7) is a secreted protein, that in humans is encoded by the SPINK7 gene. SPINK7 contains 1 Kazal-like domain. SPINK7 is probably serine protease inhibitor. Recombinant human SPINK7 is a single, non-glycosylated polypeptide chain containing 74 amino acids and fused to His-tag at c-terminus.

Human serine proteinase inhibitor Kazal-type 2 (SPINK2) functions as a trypsin/acrosin inhibitor and is synthesized mainly in the testis and seminal vesicle where its activity is engaged in fertility. The SPINK2 protein contains a typical Kazal domain composed by six cysteine residues forming three disulfide bridges. The expression of SPINK2 is closely related to cancer such as lymphomas, in that a high transcript level of SPINK2 in patients with primary cutaneous follicle center cell lymphomas have better prognosis with lower mortality. SPINK2 is necessary to neutralize proteases during their cellular transit toward the acrosome and that its deficiency induces a pathological continuum ranging from oligoasthenoteratozoospermia in heterozygotes to azoospermia in homozygotes.