Posttranslational Processing and Modification of Cathepsins and Cystatins

Table 2

Secretion profiles of cathepsins from various cells.

Macrophages	Osteoclast	Fibroblast	Cancer cells
Secretion as proforms	Secretion as mature active forms	Nonsecrete	Secreted in metastasis cells
—	Stimulated by PTH; Bone collagen degradation	I cell diseases; Secreted into serum as mature forms	Nonmetastasis cells not secreted