ADAR and cancer: On the other hand, upon IFNs response, ADAR1 deletion could activate another dsRNA sensor, PKR to induce apoptosis in several cancer cell lines.131 Furthermore, loss of ADAR1 can overcome the resistance to PD-1 checkpoint blockade as a result of a significant increase in IFNs production and immune cells, including CD4+ T cells, CD8+ T cells, NK cells, and decreasing in M2 type myeloid cells in mouse model.132