ERBB2 and cancer: For example, binding of HuR (Hu antigen R) and hnRNPA1 (heterogeneous nuclear ribonucleoprotein A1) proteins to the 3′UTR mRNA of the proto-oncogene HER2 in cancer cells overcome the inhibition of the repressive uORF located in the 5′UTR of HER2 mRNA, thus contributing in HER2 over-expression in some breast tumors [56].