BIRC5 and neoplasm: Polyethyleneimine-modified SFNPs (PEI-SFNPs) used to co-deliver doxorubicin and survivin siRNA effectively induced apoptosis in the 4T1 mouse tumor cell line and remarkably reduced the growth rate of breast tumor in 4T1 tumor bearing mice by suppressing the survivin gene (Norouzi et al., 2021).