The original publication of this paper unfortunately contained three errors in Figs. 2B and 3. In Fig. 2B, the TSS site must be counted as "+ 1" instead of "- 1". And we indicated wrong sequences in Fig. 3: the construct "Control" has a missing one "A" in the BCE sequence, and the reverse direction of BCE sequence in the construct "BCEr" must be "GCGGAGTTTCAATT", not "CGCCTCAAGTTAA". For the reasons stated herein, the authors wish to notify the readers that Figs. 2B and 3 must be interpreted as the followings.