CXCR4 and lung adenocarcinoma: Weiss et al. utilized PET imaging with 64Cu-plerixafor to examine CXCR4 expression in solid tumors, showing high CXCR4 levels in metastatic lung adenocarcinomas, further supporting the use of CXCR4-directed therapies in aggressive tumors (Weiss et al., 2017).