Clustered regularly interspaced short palindromic repeat/CRISPR‐associated Cas9 (CRISPR/Cas9) systems of bacteria and archaea have engineered for genome editing in eukaryotic genomes. In such CRISPR/Cas9 system, CRISPR RNA (crRNA) and trans‐activating CRISPR RNA (tracrRNA) were engineered into a simplified single guide RNA (sgRNA). Cas9 and sgRNA form a complex that scans through genome for the protospacer adjacent motif (PAM) sequence (predominantly 5′‐NGG‐3′) and for the sequence (ca. 18–20 nucleotides) complementary to the sgRNA, leading to double‐stranded DNA breaks (DSBs) that are exploited for site‐specific DNA alterations (Jinek et al., 2012).