CD274 and neoplasm: If “interchangeability” would be defined as achieving ≥90% sensitivity and specificity for both the 1% and the 50% tumor proportion score cut-off points, none of the studies in this meta-analysis demonstrated “interchangeability” of the Food and Drug Administration-approved assays PD-L1 IHC 22C3 pharmDx, PD-L1 IHC 28-8 pharmDx, Ventana PD-L1 (SP142), or Ventana PD-L1 (SP263) for each other.