CXCR4 and cancer: Giarra et al. (2018) designed a temperature-responsive gel loaded with SDF-1 based on methylcellulose (MC) or poloxamers with or without hyaluronic acid (HA) for the purpose of attracting CXCR4-expressing GBM cells (Figure 1 Scheme II-3-f). Haji Mansor et al. (2018), on the other hand, encapsulated the chemokine in nanoparticles composed of PLGA and a (PEG)-PLGA copolymer to achieve sustained release (Figure 1 Scheme II-3-g). However, in both papers, no in vivo assessment on the ability of SDF-1 to attract migrating cancer cells was performed.