NR4A1 and neoplasm: Average CTC count was higher among patients with HER2- tumour subtype (34 CTCs/7.5 ml blood, n: 58) compared to patients with HER2+ tumour subtype (regardless of hormone receptor status) (6 CTCs/7.5 ml blood, n: 18) (p-value, 0.002) (Fig 1D).