Regulator of sister chromatid cohesion in mitosis which negatively regulates cohesin association with chromatin. Involved in both sister chromatid cohesion during interphase and sister-chromatid resolution during early stages of mitosis. Couples DNA replication to sister chromatid cohesion. Cohesion ensures that chromosome partitioning is accurate in both meiotic and mitotic cells and plays an important role in DNA repair (By similarity). Interacts with the cohesin complex throughout the cell cycle; interacts with both chromatin-bound and soluble pools of the complex. Interacts with RAD21; the interaction is direct (By similarity). Interacts with PDS5A; the interaction is direct, cohesin-dependent and competitive with CDCA5/SORORIN (By similarity). Interacts (via FGF motifs) with PDS5B; the interaction is direct (By similarity). Interacts with a SMC1 protein (SMC1A or SMC1B) and SMC3 (By similarity). Associates with chromatin through the cohesin complex during interphase. Released in the cytoplasm from nuclear envelope breakdown until anaphase, it reaccumulates in nucleus at telophase (By similarity). Highly expressed in large pachytene spermatocytes of testis. Down-regulated by dioxin in testis. Belongs to the WAPL family. Extended N-terminus.