STAT3 and squamous cell carcinoma: EGCG has been shown to significantly downregulate STAT1 and STAT3 expression in CAL-27 human squamous carcinoma cells.58 STAT1 is upregulated in certain drug-resistant cancers and inhibition of STAT1 by EGCG in colorectal cancer cells could contribute to the antitumor actions of this drug.59 Studies in SCID mice support the in vitro finding of lack interference of cisplatin antitumor efficacy by EGCG.