BIRC5 and neoplasm: Thus, 80% (28 out of 35) of the large-sized GBMs (tumour size ⩾5 cm in diameter) were found to have positive expression of cytoplasmic Survivin, while only 43% (nine out of 21) of the small-sized GBMs (<5 cm in diameter) had positive expression of cytoplasmic Survivin.