Univariate analysis revealed that PFS after alloHCT was adversely impacted by diagnosis of MCL ± AHN (HR 3.5 [95% CI 1.7–7.5], P < 0.001), absence of a KIT D816V mutation (HR 2.5 [95% CI 1.2–5.4], P = 0.021), presence of a complex karyotype (HR 3.0 [95% CI 1.4–6.6], P = 0.006) and absence of the use of TKI prior to alloHCT (HR 0.5 [95% CI 0.2-0.9], P = 0.014). The gene discussed is KIT; the disease is mantle cell lymphoma.