MKI67 and mantle cell lymphoma: Conversely, CD5- MCL patients have been shown to have a more favorable prognosis than CD5+ MCL patients with a significantly longer progression-free survival (PFS) and a tendency for longer overall survival independently of other favorable prognostic markers such as IGHV hypermutation, absence of SOX11 expression, low Ki-67, and κ light chain restriction [27].