As reported at the molecular levels p-ERK1/2 accelerates Bik degradation and promotes anti-apoptotic Bcl-2 homolog expressions [12], [23], in this study we discovered p-ERK1/2 expression inversely correlated with Bik and positively with Bcl-Xl and Mcl-1 in breast cancer patients’ tissues. The gene discussed is MAPK3; the disease is breast cancer.