Our findings suggest that a more thorough examination, such as breast magnetic resonance imaging for CBC, can be considered in young patients with the HR–/ERBB2+ subtype at an early period after the surgery for PBC, as the short interval for developing CBC is a poor prognostic factor.17 However, the number of patients who developed CBC in this subgroup was small; therefore, multicenter studies with larger populations are needed to further validate this result. Here, ERBB2 is linked to primary biliary cholangitis.