C1QTNF9 and bacterial infectious disease: Moreover, CTRP9 knockdown reduced the frequency of Granzyme B-producing T cells (Fig. 4N,O), impaired the transcriptional upregulation of Perforin A, Granzyme B, TNF-α, and IL-6 (Fig. 4P; Appendix Fig. S8G), ultimately resulting in increased susceptibility to bacterial infection (Fig. 4Q) and elevated mortality (Fig. 4R).