HAS1 and plasma cell myeloma: However, it has been shown that high HAS1 expression is associated with poor patient survival for ovarian cancer, colon cancer, Waldenström ́s macroglobulinemia and multiple myeloma (Siiskonen et al. 2015), and its downregulation correlates with lower growth and development of bladder cancer due to lower hyaluronan production (Golshani et al. 2008).