STAT3 and cancer: To further confirm whetherYY002-binding amino acids were responsible for the anticancer activityof YY002, we overexpressed each mutant in STAT3 stable knock-downPANC-1 cells and treated the above cells with YY002, however, overexpressionof the mutants, except for an activated STAT3 mutation N647I29 that harbors high pSTAT3, failed to restorethe anticancer capacity of YY002 (Figure 2D,E), demonstrating YY002-bound amino acidsdirectly regulated its antipancreatic cancer activity.