PROK2 and mastocytoma: In recent studies, the anti-tumor efficacy of an anti-PK2 antibody has been compared to treatment with an anti-VEGF antibody and found to be nearly as effective in preventing disease progression of a transgenic mouse model of pancreatic β-cell tumorigenesis, while the combination of the two antibodies showed an even more pronounced effect in inhibiting subcutaneous growth of different human cancer cell lines (colon cancer, rhabdomyosarcoma) and mouse tumor cells (mastocytoma, lymphoma) [8], [39].