STAT1 and melanoma: Furthermore, we evaluated the relationship between TET-STAT-CD274 signaling and immunotherapeutic efficacy in anti-PD1-treated melanoma patients from the GEO database and found that compared to the corresponding pretreatment expression, TET3 (6/9), STAT1 (5/9), and STAT3 (5/9) expression after treatment was increased in more than 55–66% of PRCR patients (Fig. 4A, B).