DNMT inhibition has also been shown to result in DNA damage and G2/M phase cell cycle arrest [24, 25], and we therefore assessed changes in tumor levels of the mitotic marker serine 10–phosphorylated histone H3 (pHH3) using a previously validated quantitative immunofluorescence microscopy assay for pHH3 [13] in baseline and C1W3 biopsies. The gene discussed is DNMT1; the disease is neoplasm.