Cumulative incidence curves of TRM by day-100 biomarker thresholds and age group. Curves comparing 4 groups: high vs low CXCL9 (above [red] and below [blue] the threshold of 7 ng/mL, respectively) in either patients aged ≤10 years (solid line) or >10 years (dashed line), at post-HCT landmark day 100; ≤10, high CXCL9 (TRM, n = 0; no TRM, n = 11) vs low CXCL9 (TRM, n = 5; no TRM, n = 109), P = .48; >10, high CXCL9 (TRM, n = 5; no TRM, n = 19) vs low CXCL9 (TRM, n = 19; no TRM, n = 134), P = .21. Curves comparing 4 groups: high vs low IL1RL1 (above [red] and below [blue] the threshold of 20 ng/mL, respectively) in either patients aged ≤10 years (solid line) or >10 years (dashed line), at post-HCT landmark day 100; ≤10, high IL1RL1 (TRM, n = 4; no TRM, n = 45) vs low IL1RL1 (TRM, n = 1; no TRM, n = 75), P = .07; >10, high IL1RL1 (TRM, n = 20; no TRM, n = 74) vs low IL1RL1 (TRM, n = 4; no TRM, n = 79), P = .002. Curves comparing 4 groups: high vs low REG3α (above [red] and below [blue] the threshold of 103 ng/mL, respectively) in either patients aged ≤10 years (solid line) or >10 years (dashed line), at post-HCT landmark day 100; ≤10, high REG3α (TRM, n = 2; no TRM, n = 24) vs low REG3α (TRM, n = 3; no TRM, n = 96), P = .36; >10, high REG3α (TRM, n = 13; no TRM, n = 21) vs low REG3α (TRM, n = 11; no TRM, n = 132), P < .001. Curves comparing 4 groups: high vs low MMP3 (above [red] and below [blue] the threshold of 14 ng/mL, respectively) in either patients aged ≤10 years (solid line) or >10 years (dashed line), at post-HCT landmark day 100; ≤10, high MMP3 (TRM, n = 1; no TRM, n = 21) vs low MMP3 (TRM, n = 4; no TRM, n = 99), P = .99; >10, high MMP3 (TRM, n = 20; no TRM, n = 52) vs low MMP3 (TRM, n = 4; no TRM, n = 101), P < .001. Curves comparing 4 groups: high vs low DKK3 (above [red] and below [blue] the threshold of 62 ng/mL, respectively) in either patients aged ≤10 years (solid line) or >10 years (dashed line), at post-HCT landmark day 100; ≤10, high DKK3 (TRM, n = 1; no TRM, n = 11) vs low DKK3 (TRM, n = 3; no TRM, n = 89), P = .51; >10, high DKK3 (TRM, n = 11; no TRM, n = 20) vs low DKK3 (TRM, n = 6; no TRM, n = 111), P < .001. Curves comparing 4 groups: high vs low sCD163 (above [red] and below [blue] the threshold of 789 ng/mL, respectively) in either patients aged ≤10 years (solid line) or >10 years (dashed line), at post-HCT landmark day 100; ≤10, high sCD163 (TRM, n = 1; no TRM, n = 10) vs low sCD163 (TRM, n = 3; no TRM, n = 90), P = .36; >10, high sCD163 (TRM, n = 8; no TRM, n = 16) vs low sCD163 (TRM, n = 9; no TRM, n = 115), P < .001.