Resumen
PD-1/PD-L1 axis blockade immunotherapy leverages on assessment of tumour PD-L1 status by immunohistochemistry for identifying cancer patients? who would benefit most from this therapy. Because some PD-L1 negative cancer patients also benefit from the treatment, it has been postulated that spatial heterogeneity of PD-L1 expression in tumour tissue may reduce the predictive value of the test. Here we demonstrate for the first time the presence of PD-L1+ circulating tumor?derived microvesicles in the blood stream of high grade serous ovarian cancer patients and propose the assessment of tumor-derived circulating PD-L1+ microvesicles to be inserted in predictive algorithms for complementing tumour PD-L1 status.