The library preparation incorporates molecular identifiers (UMI) for each cDNA molecule, which allows subsequent correction for PCR bias and sequencing error, allowing a robust and quantitative annotation of each sequence in terms of CDR3 sequence and frequency (22, 23, 30); About ~1.89 x106 annotated CDR3 nucleotide beta chains were obtained, including a varied number of sequences between compartments, tissues, and infection status (SI Table 1), which positively correlates with the number of sorted cells (SI Figure 1C). The gene discussed is TRBV20OR9-2; the disease is infection.