BTK and acquired polycythemia vera: Overall, kinases that are pathogenically associated with PV acantholysis include several kinome branches such as CMGC (p38MAPK, cdk2, c‐JNK, ERK, and ASK1), ACG (PKC isoforms), CAMK (MK2 and PI3K), and TK (BTK, FAK, Src, and EGFR; Figure 3).