Fig. 4

Denucleated cancer-associated macrophage-like cells (CAMLs) detected in the fresh and frozen renal cell carcinoma samples (RCC patient 1). a Fresh sample without cryopreservation. A naked multinuclear nucleus, which might be dissociated from the original CAML, is indicated with a red arrow. b Frozen sample after cryopreservation for 7 days. To better show structural details in nuclei, we used a light-blue color for DAPI fluorescence channel. The small round cells are white blood cells; the round-shaped structures within the denucleated CAMLs may represent white blood cells that were adhered to the filter pores and overlapped with the denucleated CAMLs