CD274 and anemia: The incidence of most AEs was not increased by PD‐1/PD‐L1 inhibitors, except for a significant decrease in anaemia (all‐grade RR 0.70, P = 0.003, grade 3/4 RR 0.71, P = 0.04) and significant increase in rash (all‐grade RR 1.46, P < 0.0001, grade 3/4 RR 1.08, P < 0.0001).