CCND1 and breast cancer: CCND1 and ID1 gene expression was also correlated with EMT-associated genes including, VIM, SNAI1, SNAI2, and TWIST1. Finally, the recently established claudin-low subtype of breast cancer, which is enriched in EMT markers, was found to have a four-fold greater proportion of CCND1low/ID1high tumours compared to other breast cancer subtypes.