“…In cultured human cells, atypical chemokine receptor 4 (Ackr4) binds to Ccl19 and Ccl21, and atypical chemokine receptor 5 (Ackr5) binds to Ccl19 (Comerford et al, 2013; Friess et al, 2022; Jafarnejad et al, 2017; Sarmadi et al, 2015). However, ackr5 is not present in Xenopus (Fukui & Matsunami, 2022; Nomiyama et al, 2011). Ackr4 is a scavenger receptor of Ccl19 and Ccl21 in the human immune system, inhibiting ccl19/ccr7 or ccl21/ccr7 signal transduction (Comerford et al, 2013; Friess et al, 2022; Jafarnejad et al, 2017).…”