IL1B and neoplasm: To demonstrate that the crosstalk between tumor cells and fibroblasts mediated by IL1β induces chemoresistance, we performed a colony forming assay in transwell cocultures between different CCCL (700 cells per well; lower chamber) and NCF (50,000 cells, 24 mm inserts 0.4 nm pore size), with the addition of L-OHP.