A retrospective study by the National Cancer Database showed that for patients with 1–2+ SLNs without high risk factors (tumour ≥ 5 cm, grade 3 grade or Ki-67 ≥ 20%), the likelihood of finding ≥ 4+ LNs at the time of ALND, and thus meeting the criteria for adjuvant therapy with abemaciclib, was only 13% [88]. Here, MKI67 is linked to neoplasm.