The recurrence score summarizes the assay results as a value in the inclusive
range 0-100. It is derived from the reference-normalized gene expression assay
measurements. The measurements are weighted by regression analysis coefficients
in three training studies.<sup>1</sup>

---
<sup>1</sup> Paik, et al.,
'A Multigene Assay to Predict Recurrence of Tamoxifen-Treated, Node-Negative Breast Cancer',
*N Engl J Med* 2004; 351:2817-2826
(<a href='http://www.nejm.org/doi/full/10.1056/NEJMoa041588' target='_blank'>
http\://www.nejm.org/doi/full/10.1056/NEJMoa041588</a>).