Cathepsin B expression in invasive carcinomas was significantly higher as compared to precancerous tissue and normal tissue. Cathepsin B expression in the invasive carcinomas was positively correlated to tumor invasion depth and lymphatic metastasis. Significant regression of HeLa tumor growth in nude mice, which received HeLa cells treated with siRNA for CTSB. Here, CTSB is linked to invasive carcinoma.