While FAP-directed CAR T cells and vaccines effectively eliminated FAP+ CAFs, increased CD8+ T-cell infiltration, and decreased fibrotic stroma (Kieffer et al., 2020; Wehrli et al., 2024; Pure and Blomberg, 2018; Wang et al., 2014), their clinical application was limited by on-target/off-tumor toxicity due to FAP expression in healthy tissues (Tran et al., 2013). Here, FAP is linked to neoplasm.