For invasive cancers, published studies consistently show, independent of study design and comparison group, a more favourable pattern of characteristics in screen-detected cancer, such as higher proportion of small tumour size, no regional lymph nodes, low histological grade, low Ki-67, positive oestrogen (ER) and progesterone (PgR) receptors and negative HER2 receptor.10, , , , , , , , , , , , –23 Among surrogate molecular sub-types the screen-detected had a higher proportion of luminal A-like cancer and lower proportion of HER2-positive and triple negative sub-type.11,12,14,20,23. The gene discussed is ERBB2; the disease is cancer.