EphB4 expression fully overlapped with the IGF-II secretion status along with the expression of the two IGF-II signal transducing tyrosine kinase receptors (IRA and IGF1R) in all the overtly aggressive cancer cell lines we tested including mesothelioma, breast carcinoma, prostate carcinoma, sarcoma, human hepatoma and colon carcinoma (Table 1) but in normal immortalized cells (MCF-10A). This evidence concerns the gene IGF1R and mesothelioma.