ST6Gal-1 is increased in some rectal cancer patient-derived xenograft (PDX) models after chemoradiationA, H&E staining of PDX (2), compared with the original tumor material obtained at the time of biopsy (1), shows similar histology. B, decreased tumor volume compared with vehicle in mice treated with capecitabine and radiation (black bars indicate treatment days) when PDX models are implanted in the flank and treated for 2 weeks. C, ST6Gal-1 increases after chemoradiation in two of three treated PDX models compared with vehicle (NP33: 2.40-fold increase, N = 4, p = 0.01; NP26: 2.18-fold increase, N = 3, p = 0.01; NP86: 0.88-fold decrease, N = 3, p = 0.33).