RAB27A and neoplasm: PD‐L1 has previously been shown to be secreted out of tumor cells via EVs.[17] We showed that the cytosolic PD‐L1‐GFP puncta indeed exhibited strong colocalization with various MVBs or EV markers (e.g., CD63, TSG101, and Rab27a), in PD‐L1‐GFP‐expressing cells (Figure 2A).