EREG and breast cancer: In one study using normal human epidermal keratinocytes, 2 nM EREG induced ERK phosphorylation more strongly than 10 nM EGF (Draper et al, 2003), whereas in another study using MCF-7 mammary cancer cells, 10 μM EREG and 16 nM EGF induced ERK phosphorylation to a similar level (Freed et al, 2017).