In both METABRIC and TCGA cohorts, high ISG15 mRNA expression was correlated with LVI and other variables of poor prognosis, including high tumour grade, hormone receptor negativity [ER and PR], HER2 positivity and expression of EGFR and stem cell CD44) marker (Table 1). High ISG15 expression was also associated with larger tumour size and positive nodal status in the METABRIC cohort (Table 1). Here, PGR is linked to neoplasm.