PLCH2 and rheumatoid arthritis: We speculated that PLCη2 might modulate the tumor-like transformation and aggressive phenotype of FLSs; thus, we investigated the contribution of PLCη2 to proliferation and apoptosis by transfecting OA FLSs with an shRNA against Plch2 transcripts (shPLCη2) or infecting RA FLSs with Ad-PLCη2.