However, published patient breast cancer datasets [20, 21, 43], show a clear link between increased YB-1 expression and amplified KRAS, but no association with HRAS or NRAS. In the present study, we provide evidence of a similar loss of a normal acinar architecture by KRASG12D-transduced human mammary cells both in 3D cultures in vitro and following transplantation into mice. This evidence concerns the gene KRAS and breast cancer.