Remarkably, although the overall frequency of TRBV9+ T cells in peripheral blood remained extremely low (Fig. 2l), deep targeted profiling of the TRBV9 TCR repertoire revealed the reappearance of ankylosing spondylitis-associated CDR3 motifs at this time (Fig. 2m, red arrow). This evidence concerns the gene TRBV9 and ankylosing spondylitis.