Furthermore, we noted that Cdk6, which is essential for the egress of HSCs from quiescence21, and Plac8 and Cd53, which are involved in enhanced cell cycling22,23, were upregulated on LT-HSCs in SpA (Fig. 2c), corresponding with the HSC increase observed in response to arthritis-derived inflammatory signals. This evidence concerns the gene PLAC8 and Arthritis.