CDK4 and neoplasm: Although the presence of functional cellular PIM1 activity for LY2835219 in these hematological tumor types that are presumably sensitive to PIM inhibition seems possible, the very similar MV4-11 and Jeko-1 xenograft efficacy observed for this molecule with respect to another CDK4/6 inhibitor without PIM1 activity (Fig. 4c, Table 2) suggests a modest effect of this activity compared to CDK4/6 for this particular tumor type, possibly due to compensation by PIM2 or other kinases.