In a phase I study of a 3 + 3 dose escalation to treat small-cell lung cancer patients, sonidegib combined with cisplatin and etoposide sustained PFS in patients with Sox2 amplification.224 These combinations in a phase II trial for patients with recurrent medulloblastoma resulted in a complete or partial response in 50% of patients612 and have been used for other cancer treatments in phase I/II clinical trials, such as NCT02111187 for prostate cancer, NCT02027376 for breast cancer, and NCT02195973 for recurrent ovarian cancer. Here, SOX2 is linked to breast cancer.