Nevertheless, the blockade of PD-1 may shift the balance of the binding of PD-L2 with its other partner, repulsive guidance molecule b (RGMb), which can lead to pneumonitis.380 This is also confirmed by the fact that patients treated with PD-1 inhibitors have a higher incidence of pneumonitis than patients who received PD-L1 inhibitors.390,391. This evidence concerns the gene PDCD1 and pneumonitis.