MYC and breast carcinoma: Interestingly, a study examining the contribution of Ras and c-MYC to breast cancer tumorigenesis compared breast cancer initiation by c-Myc and K-Ras (G12D) in early malignancy in vivo, and intriguingly found that while both could lead to CA in tumors, only K-Ras could induce CA during pre-malignancy.