For comprehensive T-cell immunity, T cells need to recognize their target through the T-cell receptor (TCR), and subsequently exert function. Antigen specificity is mainly encoded within the complementarity determining region 3 (CDR3) of the TCRα and β-chains. Over the past years, increasing efforts have been made (i) to identify the full TCR sequence of both (α and β) chains and (ii) to characterize the phenotype of individual T cells down to their ‘transcriptional state’. Full TCR sequencing has initially relied on classical RT–PCR-based approaches 1, 2 or TCR genomic DNA capture. 3 Recently, identification efficiency for B-cell receptors has neared perfection using emulsion PCR after flow focusing-driven mRNA capture. 4 The group of Mark Davis 5 complemented the RTPCR approach of TCR sequencing with phenotypic characterization in single cells. The study was a milestone in combining TCR identification with phenotypic characterization, but it relied on primers for both TCR and for a limited number of T-cell function-related genes. Simultaneously, single-cell RNA sequencing (scRNA seq) had emerged as an extremely powerful tool to reveal the full transcriptional status of single cells in a universal and rather unbiased fashion. 6