Subsequently, the same group further optimized the preparation process to increase the PTX encapsulation efficiency to 90% and verified its anti-tumor effect in the SKOV3-tr ovarian cancer drug-resistant nude mice model, where the survivin siRNA/PTX PM co-delivery system resulted in a 4-fold reduction in tumor volume compared to a single drug, as well as down-regulated the expression of survivin and promoted drug enrichment in tumor tissues [89]. Here, BIRC5 is linked to ovarian carcinoma.