There is no significant publication bias for the following analysis: mRNA expression of SIX family members: breast cancer risk: SIX1: Begg test P = 0.707, Egger test P = 0.568; SIX3: Begg test P = 0.734, Egger test P = 0.474; SIX4: Begg test P = 0.707, Egger test P = 0.381. The gene discussed is SIX4; the disease is breast cancer.