CD4 and breast cancer: In animal breast cancer models lapatinib promotes tumor infiltration by CD4+ CD8+ IFN-γ-producing T-cells through a Stat1-dependent pathway, suggesting that this immune activation can play a role in lapatinib antitumor activity [88] Fedele et al. [89] showed that a combination of SHP2 and KRASG12Ci awarded good tumor control and increased T cell infiltration in an orthotopic model of lung cancer.