We previously demonstrated, using tumorigenic cell lines derived from breast cancers, that the mAb AIIB2, against ß-1integrin (CD29), did not inhibit cell multiplication and the formation of clonal aggregates resulting from cell multiplication in the 3D Matrigel model using the tumorigenic mammary tumor-derived line MDA-MB-435-Br1 [19]. This evidence concerns the gene ITGB1 and breast cancer.