FNDC3B and systemic sclerosis: Furthermore, <i>in vitro</i> experiments demonstrated that FNDC3B and NNMT were significantly upregulated in PD- and SSc-like cellular models, and their silencing alleviated ferroptosis-associated cellular injury.<h4>Conclusion</h4>This study highlights potential shared ferroptosis-related genes, regulatory networks, and candidate therapeutic compounds associated with PD and SSc, providing new insights into their molecular connections.