The Hodgkin cell line U-HO1 was established from a malignant pleural effusion of a 23-yr-old male patient during the end stage of refractory nodular sclerosing classical Hodgkin lymphoma (cHL). Since its establishment in 2005, U-HO1 has maintained stable characteristics in vitro and has a doubling time of about 4 days under standard culture conditions. U-HO1 forms typical Reed/Sternberg cells in suspension, is EBV negative, lacks HLA-ABC- but expresses HLA-D- proteins/CD74 and surface exposes CD15 together with CD30 in the absence of CD19 and CD20. Karyotype analysis of U-HO1 revealed a hyperdiploid karyotype with multiple clonal aberrations. Most significant is an elongated chromosome 2, der(2)t(2;10)(q35;q16.1)add(2)(p13). CGH analysis revealed the following imbalances: ish cgh dim(1)(p13p31)(p12q21), enh(2)(p13p23), dim(4)(q31.3qter), enh(6)(q22q27), enh(12), enh(18),enh(20)(q13.1pter). FISH analysis showed about six-fold amplification of REL and BCL-11A, thus, U-HO1 is prototypical for cHL in every aspect tested so far. Compared to other HL cell lines, U-HO1 proved far less genetically aberrant suggesting that U-HO1's imbalances suffice to cause the full-blown phenotype of primary refractory cHL.