Indeed, additional stainings on primary tumor sections showed that p-Stat3 levels were significantly reduced in the chitin- and chitin + anti-PD-1-treated compared to untreated and anti-PD-1-treated 4T1 primary tumors, but this reductive effect was not detected in the low CLP-producing 66cl4 primary tumors (Fig. 4A). Here, PDCD1 is linked to neoplasm.