Immunohistochemical analysis of SRSF1 and SRSF2 proteins expression in non-small cell lung cancer according to histological subtype.

Abbreviations: ADC, adenocarcinoma; SCC, squamous cell carcinoma; NSCLC, non-small cell lung carcinoma. Immunostaining scores were calculated by multiplying the number of labeled cells (0–100%) by the level of intensity (1–3). According to this, tumor samples were grouped into several classes (see ‘Materials and Methods’ section). For SRSF1 and SRSF2, class 0 (normal expression as compared to normal lung), class 1 (high staining considered as overexpression). For phospho-SRSF2, class 0 (normal expression), class 1 (moderate overexpression) and class 2 (high overexpression). Statistical analysis was done using Fisher’s exact test.