TULP1 and retinal disorder: We present a patient with an underlying tubby-related protein 1 (TULP1) cancer-associated retinopathy who lost vision following initiation of atezolizumab for small-cell lung cancer. This 75-year-old man presented with no light perception, paramacular and peripheral retinal pigmentary changes, attenuated outer retina, and extinguished rod and cone responses.