Engineering immune cells remained a high-velocity area. A report described engineered T cell receptors with built-in ICOS signaling that aimed to deliver long-lasting anti-tumor activity, targeting a central limitation of adoptive cell therapies: durability in solid tumors. Complementing that, a Nature Immunology study found that activating T cells inside tumors could clear tumors regardless of whether the T cells recognized the specific antigen, challenging the assumption that antigen specificity is mandatory for tumor control. On the tumor microenvironment side, work mapping myeloid cell identity changes across cancers introduced a myeloid damage response index framework to move beyond abundance-only views of tumor-infiltrating myeloid cells. Together, these studies shift the focus toward immune activation state, engineered co-stimulation, and dynamic cell programs as actionable levers rather than static cell counts.