Protein expression and NK cytotoxicity after HSCT. Functional analyses were correlated with the level of DC. Because the depicted assays had been performed with NK cells, CD56⁺ DC (□) is shown if available, otherwise the overall DC (●) is shown. (A) The results of the NK CD107a degranulation assay without interleukin-2 stimulation (FHL3-5, GS2, and CHS), expression of perforin (FHL2), SAP (XLP1), and XIAP (XLP2) were grouped into absent, reduced, and normal, according to local laboratory standards. (B) The percentage of degranulating (CD107a⁺) cells and the DC show a significant positive correlation (Spearman P = .005, ρ = .71). (C) NK cytotoxicity results were grouped into absent, reduced, and normal according to local laboratory standards. There was substantial overlap of DC level between the groups (P = .11). PRF, perforin.