KRAS and ovarian cancer: For example, oncogene EGFR also exists in exosomes from prostate cancer patients.157 miRNAs such as miR‐21 and miR‐141, which was previously known as diagnostic markers for ovarian cancer, were also present in exosomes from ovarian cancer patients.141 KRAS and p53 mutations in exosomal DNA of pancreatic cancer also could predict the treatment option and therapy resistance.158