28. The molecular mechanism of the gene expression revealed the role of specific transcription factors, promoters, enhancers, and cofactors involved. Which experiment is incorrect? (A) The transcription factor-binding sequences can be determined with chromatin-immunoprecipitation (IP) followed by DNA sequencing. (B) The promoter and enhancer were cloned from the cDNA library for the reporter assay. (C) The transcription factor was knocked down by siRNA for the loss-of-function analysis. (D) The transcription factor was overexpressed with a viral vector for the gain-of-function analysis. (E) The transcription factor-associated cofactors were identified by the IP-Mass Spectrometry (MS) analysis.