Quantitative Reverse-Transcription PCR Protocol

The methods of quantitative reverse-transcription PCR were previously described^{20 (link),29 (link)}. For Raji and Jurkat clones, total RNA was extracted using the RNeasy kit (Qiagen) and first-strand complementary DNA was synthesized using the High-Capacity Complementary DNA Reverse-Transcription Kit (Thermo Fisher Scientific). Reverse-transcription PCR to detect each transcript was performed using primers shown in Supplementary Table 4 and FastStart Taq polymerase (Sigma-Aldrich, St. Louis, MO, USA). To achieve linear amplification, 21, 27, 29, and 31 cycles were found to be optimal in preliminary experiments for GAPDH, POU2AF1, COLCA1, and COLCA2, respectively. Quantitation of each transcript was performed using the Agilent 2100 Bioanalyzer (Agilent Technologies, Palo Alto, CA, USA). These experiments were repeated 3 times with essentially identical results.