PIK3CA and Takayasu arteritis: Our analysis identified two subgroups in Ta tumors: one with FGFR3 alterations linked to LG tumors and favorable outcomes, and another with alterations in ERBB2, PIK3CA, and ERBB3 mutations, and FGFR1, CCND1, and MYC amplifications, associated mostly with HG tumors and poorer prognosis.