PDLIM2, Fbw7, and constitutive photomorphogenic 1 (COP1) were identified as E3 ligases for STAT3 in T helper 17 cells, diffuse large B-cell lymphoma (DLBCL) cells, and prostate cancer cells, and several proteins, including TMF/ARA160, are involved in proteasomal STAT3 degradation39–43. Here, COP1 is linked to prostate carcinoma.