RPS6KA1 and plasma cell myeloma: Given the importance of AS160 in the regulation of GLUT4 trafficking, the identification of a splice variant of AS160 displaying a diminished propensity for GLUT4 retention, and the knowledge that the AGC kinases AKT [6], RSK [7], and SGK [8] are constitutively active in myeloma, we sought to determine whether AS160 deregulation contributes substantively to the basal activation of GLUT4, that we have previously demonstrated in myeloma cells [9].