ERBB2 and breast cancer: Moreover, a substantial upregulation of EPYC mRNA expression was observed in late-stage (III+IV) breast cancer patients compared to early-stage (I+II) patients, as depicted in Fig. 4C. Fig. 4D shows that CHRNA6 mRNA expression was higher in patients over 50 years of age, as well as in patients with PR-positive and HER2-positive status.