Any process that stops, prevents, or reduces the frequency, rate or extent of the phosphorylation of a serine residue of a STAT (Signal Transducer and Activator of Transcription) protein.
synonyms:
inhibition of serine phosphorylation of STAT3 protein,
negative regulation of serine phosphorylation of STAT3 protein,
downregulation of serine phosphorylation of STAT3 protein,
down-regulation of serine phosphorylation of STAT3 protein,
GO:1903262,
down regulation of serine phosphorylation of STAT3 protein
