These results show that FPRs, beyond their role in host antimicrobial defense, also exert important effects on cell cycle progression and dermal fibroblast proliferation, after interacting with the SRSRY domain of uPAR, confirming our hypothesis that FPRs/uPAR crosstalk plays a crucial role in many pathogenetic aspects of SSc. Here, PLAUR is linked to systemic sclerosis.