KRAS and Miyoshi myopathy: After first confirming the anti-pT148 KRAS antibody could specifically detect T148 phosphorylation on KRASA146T (Fig. S4C), we found that AMO1 and H1112 MM cells harboring KRAS A146 mutations had higher basal levels of KRAS T148 phosphorylation relative to XG7 and RPMI 8226 bearing KRAS G12 mutations (Fig. 4E).