PCSK9 and mesothelioma: In BLCA (P < 0.01), KIRP (P < 0.001), STAD (P < 0.01), and THCA (P < 0.001), the expression level of PCSK9 was enriched in the T3&T4 subgroup than in the T1&T2 subgroup, while the opposite result was identified in mesothelioma (MESO) (P < 0.05) (Figure S1C).