Ni exposure induced miR-21 expression via activating the epidermal growth factor receptor EGFR/NF-κB signaling pathway; upregulated miR-21, in turn, suppressed the expression of two miR-21 target genes, SPRY2 and reversion-inducing cysteine-rich protein with kazal motifs (RECK), and promoted lung cancer cell invasiveness [10]. The gene discussed is EGFR; the disease is lung cancer.