CD44 and small cell lung carcinoma: To target the heterogeneous compositions of SCLC-NE and SCLC-non-NE malignant cells, we developed a combinational treatment strategy that composed of etoposide and cisplatin (EP), a conventional chemotherapy for SCLC, in combination with silibinin (a major bioactive component of the plant Silybum marianum) that has been studied extensively for its efficacy in cancer by inhibiting CD44 promoter activity.37,38 The addition of silibinin greatly enhanced the cancer inhibition efficacy of chemotherapy for SCLC both in vitro and in vivo (Supplementary Fig. 5f–h).