In PC cell lines, FBP1 inhibited the STAT3-dependent PD-L1 expression: FBP1 competitively sequestered the unphosphorylated STAT3, significantly decreased the STAT3 occupancy on the genomic locus of CD274 (PD-L1) gene, and downregulated the expression of PD-L1. The gene discussed is CD274; the disease is pachyonychia congenita.