ESR1 and invasive ductal breast carcinoma: Subgroup analysis revealed that low CCBL2 expression was correlated with low OS in patients with ER-positive BC (p = 0.0005), PR-positive BC (p = 0.0001), HER-2-negative BC (p = 0.0011), infiltrating ductal carcinoma (p = 0.0023), infiltrating lobular carcinoma (p<0.0001), and luminal A (p = 0.0250) (Fig 5).