STAT3 and small cell lung carcinoma: Our experimental results show that the forced overexpression of STAT3 activates YAP and its downstream genes CTGF and CYR61, but inhibiting STAT3 by siRNA did not decrease YAP, CTGF and CYR61 mRNA expressions in the SCLC cell line H209 with concurrent STAT3 and YAP expression.