Figure 4. PPP3CA expression in UM. A: The expression level of PPP3CA mRNA was measured by semi-quantitative RT–PCR in the TP31 cell line, UM primary tumors (Tumors), and UVM. B: The expression level of the PPP3CA protein was measured by western blot in the TP31 cell line, UVM, and UM primary tumors (left panel: pool of protein extracts from UM primary tumors; right panel: individual UM primary tumors). A new splice variant was detected, which lacks parts of the NH₂-terminal and catalytic domains after the deletion of exon 2 (PPP3CAΔ2). The 18S rRNA was used as internal control of amplification (489 bp). Actin was used as a protein loading control. Data are representative of three independent experiments.