These include the entire tumor microenvironment (TME, originating from the host mouse) and its constituents, such as the tumor vasculature which permits access of the liposomes to the tumors, the tumor associated macrophages (TAMs), which can phagocytose the liposomes irrespective of functionalization [34] and the tumor associated fibroblasts (TAFs) based on FAP expression. Here, FAP is linked to neoplasm.