SOX2 and ovarian serous adenocarcinoma: PRKCI gene locates on chromosome 3q26, which contains several known oncogenes, including PIK3CA, SOX2 and ECT2. Amplification of 3q26 is one of the most prominent copy number variation features that potentially drives the tumorigenesis in several types of solid tumors [23], including high-grade serous ovarian cancer [24].