CCL4 and glioblastoma: Probably due to the use of highly hypoxic conditions, in our analyses, even the levels of chemokines with well-established overproduction in hypoxia (such as CXCL8) still did not exceed those at 21% O2, and it is certainly worth noting that they still remained very high in the co-cultures for CXCL8, CCL2, CX3CL1, chemerin, and CXCLIt is also interesting that in the 3D-bioprinted GBM cell lines, we obtained dramatically higher levels of secreted CXCL8 and, to a lesser extent, also CCL3, CCL4, chemerin, and CXCL9 than we determined in neurosphere primary cultures (Supplementary Figure S2).