ACTA1 and neoplasm: To link lnc‐FSD2‐31:1 and CAFs activation, primary CAFs isolated from PDAC patient tissues were validated, and a monoculture system including tumor cells and CAFs was established (Figure 2E–G, Figure S2A, Supporting Information).[17c] After two cell types were incubated together, the expression level of α‐SMA in CAFs was significantly negatively correlated with the expression level of lnc‐FSD2‐31:1 in tumor cells (Figure 2H, Figure S2B–D, Supporting Information).