CCND1 and neoplasm: Major differences in the amount of CCND1 mRNA were observed (NCCND1 from 3.3 to 43.7); 19 tumours (14.2%) had an expression level three to five times higher than that of normal breast tissue, while 15 tumours (11.2%) contained amounts five to 10 times higher, six tumours (4.5%) 10 to 20 times higher, and four tumours (3.0%) more than 20 times higher.