CD274 and neoplasm: TPS quantification in NSCLC can be viewed as a combination of three different tasks: (1) localization of cells within the image, (2) classification of individual cells into PD-L1 negative tumor cells, PD-L1 positive tumor cells or ‘other’ (i.e. ‘to be excluded’) and (3) finally calculating a ratio of the positive versus the total number of tumor cells.