Rectificaton of minor mistakes regarding the “Kit name” and “instrument name” in the article Shabeesh Balan, RIKEN- Brain Science Institute 29 December 2014 1. The kit used for RNA isolation from blood cells was RiboPure™-Blood Kit (Life Technologies Co., Carlsbad, CA, USA). (p. 3, first paragraph, line 7), 2. The name of the digital PCR system used was QuantStudio™ 3D Digital PCR System (Life Technologies Co., Carlsbad, CA, USA) (p.3, first paragraph, line 9). Competing interests No competing interests to declare.