CXCR4 and neoplasm: Inactivation of Raf kinase inhibitory protein during tumor expansion results in higher expression of BACH1 and its target genes C-X-C chemokine receptor type 4 (CXCR-4) and matrix metalloproteinase1 (MMP1), established drivers of tumor progression and metastasis (Foley & Kuliopulos, 2014; Mishan et al, 2016).