EFEMP1 and Pleural effusion: This aligns with previous studies reporting limited diagnostic utility of pleural effusion fibulin-3 levels for MPM.16,19,21 Elevated fibulin-3 expression in MPM tumour cells likely contributes to increased plasma and pleural effusion levels, yet no significant correlation was found between fibulin-3 levels in these two compartments in our study, consistent with earlier findings.15,21