GM-CSF overexpressing and GM-CSF treated tumors exhibited elevated gelatinolytic activities: In tumors of GM-CSF negative cells, gelatinolytic activity was mainly located in stromal parts, whereas tumors of GM-CSF overexpressing cells or GM-CSF treated tumors exhibited a signal for gelatinolytic activity not only in the stromal compartment but also in the tumor (Fig. 4A and B). This evidence concerns the gene CSF2 and neoplasm.