Within this subgroup of cancers, CK-5/6 was positive in 33% of 167 cancers (P < 0.0005), CK-14 in 35% of 161 cancers (P < 0.0005), and CK-17 in 10% of 158 cancers (P = 0.001), as compared with 9%, 11% and 4%, respectively, among the tumours in which one or both of the markers (ER of HER2) was positive. Here, ERBB2 is linked to cancer.