The present invention relates to : - use of a 2,3-dihydroimidazo[1,2-c]quinazoline compound, or of a pharmaceutical composition containing same, as a sole active agent, or of a combination of a) said compound or a pharmaceutical composition containing said compound and b) one or more further active agents, for the preparation of a medicament for the treatment or prophylaxis of non-Hodgkin’s lymphoma (NHL), particularly 1st line, 2nd line, relapsed, refractory, indolent or agressive non-Hodgkin’s lymphoma (NHL), in particular follicular lymphoma (FL), chronic lymphocytic leukaemia (CLL), marginal zone lymphoma (MZL), diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), transformed lymphoma (TL), or peripheral T-cell lymphoma (PTCL) ； - combinations of a) said compound and b) one or more further active agents ； - a pharmaceutical composition comprising said compound as a sole active agent for the treatment of non-Hodgkin’s lymphoma (NHL), particularly 1st line, 2nd line, relapsed, refractory, indolent or agressive non-Hodgkin’s lymphoma (NHL), in particular follicular lymphoma (FL), chronic lymphocytic leukaemia (CLL), marginal zone lymphoma (MZL), diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), transformed lymphoma (TL), or peripheral T-cell lymphoma (PTCL) ； - a pharmaceutical composition comprising a combination of a) said compound and b) one or more further active agents ； - use of biomarkers involved in the modification of the expression of PI3K isoforms, BTK and IKK,, BCR activation, BCR downstream activation of NFκB pathway, c-Myc, EZH2, for predicting the sensitivity and/or resistance of a cancer patient to said compound and providing a rationale-based synergistic combination as defined herein to increase sensitivity and/or to overcome resistance ； and - a method of determining the level of a component of one or more of the expression of PI3K isoforms, BTK and IKK,, BCR activation, BCR downstream activation
