All MPM samples will be subjected to immunohistochemistry with CD74 and VEGF antibodies.

The VEGF will be scored using a 0-3 scoring system to represent the percentage of cytoplasmic positively stained cells in the tumor portion, as follows: 0-10%, 11-30%, 31-60% and 61-100% positive staining correspond to score 0, 1, 2 and 3 respectively. Both CD74 and VEGF immunohistochemical markers will be furtherly categorized in the statistical analyses as none (0)/low (1) vs medium (2)/high expression(3).

The CD74 expression will be recorded in the tumor and the stroma semiquantitatively using the histoscore method using four representative fields with the final score resulting from the percentage of tumor cells staining positively multiplied by the staining intensity grade.

The paraffin blocks of the patients will be tested for CD74 and VEGF before starting treatment using IHC and the results will be correlated with the outcome of treatment during evaluation.

All MPM samples will be subjected to immunohistochemistry with CD74 and VEGF antibodies.

The VEGF will be scored using a 0-3 scoring system to represent the percentage of cytoplasmic positively stained cells in the tumor portion, as follows: 0-10%, 11-30%, 31-60% and 61-100% positive staining correspond to score 0, 1, 2 and 3 respectively. Both CD74 and VEGF immunohistochemical markers will be furtherly categorized in the statistical analyses as none (0)/low (1) vs medium (2)/high expression(3).

The CD74 expression will be recorded in the tumor and the stroma semiquantitatively using the histoscore method using four representative fields with the final score resulting from the percentage of tumor cells staining positively multiplied by the staining intensity grade.