PIR and cancer: STAT3 is an important regulator in cancer; substantial evidence suggests that STAT3 is constitutively activated in many cancers, significantly contributing to tumor development and metastasis, and is associated with cancer severity and unfavorable prognosis.[42] Given that piR‐RCC inhibits RCC progression by down‐regulating STAT3 expression, we investigated whether the combination of piR‐RCC overexpression and stattic (a STAT3 inhibitor) would synergistically inhibit RCC progression.