H2BC21 and osteosarcoma: Screening of a panel of different tumour cells and also control diploid cells for mitotic H2B S6ph showed frequent phosphorylation during late anaphase for cell lines such as HT-29 (colorectal adenocarcinoma) and U2OS (osteosarcoma), while other tumour cells showed proper timing of this phosphorylation (figure 7a).