CDK7 was detected by immunohistochemistry (IHC) according to standard methods. The breast cancer tissue microarray (HBre-Duc140Sur-01) was obtained from Shanghai Outdo Biotech (Shanghai, China), and included tissue samples collected from January 2001 to August 2004. The tissue microarray had been previously described (21 (link)). The follow-up time was up to July 2013.