CCND1 and mantle cell lymphoma: However, the differential phenotype and IGHV usage pattern of B-PLL compared to CLL or SMZL and the recognition of B-PLL cases with no evidence of previous small B-cell neoplasm and well-documented absence of CCND1/D2 or D3 overexpression suggest that a B-cell neoplasm with B-PLL features distinct from MCL may exist [47, 51, 55].