"TYMS was absent in 100% of circulating tumor cells (CTCs) from locally advanced rectal cancer patients with pathologic complete response yet was expressed in 83% of non-responders prior to surgery (S2). RAD23B was expressed in CTCs from 75% of non-responders prior to neoadjuvant chemoradiation (S1) and in 100% of non-responders at S2. 100% of non-responders expressed TYMS mRNA at both timepoints."xsd:string