CCND1 and breast cancer: Our own analysis of 816 breast tumors from The Cancer Genome Atlas (TCGA) has revealed that NDRG1 is one of the six most commonly amplified genes in breast cancer, which include MYC, RAD21, EXT1, NDRG1, UBR5, CCND1 (Figure 4A) [92]; NDRG1 was found to be amplified in 17% of patients, NDRG2 in 0.5%, NDRG3 in 2.9%, and NDRG4 in 0.9% (Figure 4B).