STAT3 and cancer: As to the first biomarker (PAL of Growth hormone signaling pathway (gene expression via SRF, ELK1, STAT5B, CEBPD, STAT1, STAT3), Figure 6), growth hormone signaling has been previously associated with the local activity of immune system (52, 53) and with the efficacy of ICI treatment in human cancers (54, 55).