Expression of miR-342 and miR-520g in breast tumours. RQ-PCR detection analysis shows that expression levels of miR-342 are increased in: (a) oestrogen receptor (ER)-positive tumours compared with ER-negative tumours (P = 0.04), (b) v-erb-b2 erythroblastic leukaemia viral oncogene homolog 2 receptor (HER2/neu)-positive compared with HER2/neu-negative tumours (P = 0.001), and (c) luminal-B subtype of breast tumours (P = 0.001). (d) miR-520g expression is increased in ER-negative tumours compared with ER-positive tumours (P = 0.005) and in progesterone receptor (PR)-negative tumours compared with PR-positive tumours (P = 0.032). MicroRNA expression presented as log10 of the relative quantity. *P < 0.05, **P < 0.005.