REC8 and cancer: In addition, they show that the expression of REC8 in human cancer cell lines triggers a mild mitotic phenotype, so its presence is permissible in tumors, while the expression of RAD21L induces a cell cycle arrest that leads to chromosomal instability, which would explain its underrepresentation in tumors, but would not rule out its transient activation in early oncogenic events [136] (see also Table S1 and Figure S1).