The present invention pertains generally to the field of therapeutic compounds. More specifically the present invention pertains to certain 1-(5-tert-butyl-2-aryl-pyrazol-3-yl)-3-[2-fluoro-4-[(3-oxo-4H-pyrido[2,3-b]pyrazin-8-yl)oxy]phenyl]urea compounds (referred herein as “TBAP compounds”) that, inter alia, inhibit RAF (e.g., BRAF, CRAF, etc.). The present invention also pertains to pharmaceutical compositions comprising such compounds, and the use of such compounds and compositions, both in vitro and in vivo, to inhibit RAF (e.g., BRAF, CRAF, etc.); and to treat disorders including proliferative disorders; cancer (including, e.g., malignant melanoma, colorectal carcinoma, pancreatic adenocarcinoma); inflammation; immunological disorders; viral infections; fibrotic disorders; disorders associated with a mutated form of RAF (e.g. BRAF, CRAF, etc.); disorders ameliorated by the inhibition of RAF (e.g., BRAF. CRAF, etc.); disorders ameliorated by the inhibition of mutant BRAF; disorders ameliorated by the inhibition of BRAF and CRAF; disorders associated with RAS mutations and/or MAPK pathway activation; disorders ameliorated by the inhibition of SRC, p38, FGFRA, VEGFR-2 (KDR), and/or LCK; etc.