Kallikrein-related peptidases (KLKs) are critical regulators of the tumour microenvironment. KLKs are proteolytic enzymes regulating multiple functions of bioactive molecules including hormones and growth factors, membrane receptors and the extracellular matrix architecture involved in cancer progression and metastasis. Perturbations of the proteolytic cascade generated by these peptidases, and their downstream signalling actions, underlie tumour emergence or blockade of tumour growth. Recent studies have also revealed their role in tumour immune suppression and resistance to cancer therapy. Here, we present an overview of the complex biology of the KLK family and its context-dependent nature in cancer, and discuss the different therapeutic strategies available to potentially target these proteases.

激肽释放酶相关肽酶 (KLK) 是肿瘤微环境的关键调节剂。KLKs 是调节生物活性分子的多种功能的蛋白水解酶，包括激素和生长因子、膜受体和参与癌症进展和转移的细胞外基质结构。这些肽酶产生的蛋白水解级联的扰动及其下游信号作用是肿瘤出现或肿瘤生长阻断的基础。最近的研究还揭示了它们在肿瘤免疫抑制和对癌症治疗的抵抗中的作用。在这里，我们概述了 KLK 家族的复杂生物学及其在癌症中的背景依赖性，并讨论了可用于潜在靶向这些蛋白酶的不同治疗策略。