BIRC5 and neoplasm: The density of tumor cells with cytoplasmic Survivin expression ranged between 273.73 tumor cells per mm2 (3.4%; group 2) and 431.69 tumor cells per mm2 (6.2%; group 4) with no difference between groups and an overall median of 386.28 positive tumor cell per mm2 (5.1%; Figure 3).