Formula I (Ia and Ib) compounds wherein (i) X1 is N and X2 is S, (ii) X1 is CR7 and X2 is S, (iii) X1 is N and X2 is NR2, (iv) X1 is CR7 and X2 is O, or (v) X1 is CR7 and X2 is NR2, including stereoisomers, tautomers, metabolites and pharmaceutically acceptable salts thereof, are useful for inhibiting the delta isoform of PBK, and for treating disorders mediated by lipid kinases such as inflammation, immunological, and cancer. Methods of using compounds of Formula I for in vitro, in situ, and in vivo diagnosis, prevention or treatment of such disorders in mammalian cells, or associated pathological conditions, are disclosed.
