This invention relates to the use of a compound 2,3-dihydroimidazo [1,2-c] quinazoline or a pharmaceutical composition which contains it, as a separate active ingredient or combination a) of the above compound or pharmaceutical composition which contains said compound and b) one or more additional active ingredients for the preparation of a medicament for the treatment or prevention of endometrial cancer (which is further abbreviated as “EC”), in particular the EU 1st line, 2nd line, recurrent, resist ntnogo, type I or type II, or endometriosis； combinations of a) the above compound and b) one or more additional active substances； pharmaceutical composition, which includes the specified connection as a separate active ingredient for the treatment of endometrial cancer (which is further abbreviated as "EC"), in particular the EC of the 1st line, 2nd line, recurrent, resistant, type I or type II or endometriosis； a pharmaceutical composition that includes a combination of a) the above compound and b) one or more additional active substances； biomarker applications, which are biomarkers of the loss of the PTEN or FBXW7 anti-oncogene, to predict the sensitivity and / or resistance of a patient who suffers from cancer to the above compound, and to provide a rational dose to increase sensitivity and / or to overcome resistance； pts of pik3ca, pik3cb, pik3cd, pik3cg, pik3r1, pik3r2, pik3r3, pik3c2, pik3r1, pik3cg, pik3r1, pik3r2, pik3r3, pik3rg, pik3r3, pik3rg, pik3r1, pik3rg, pik3r5 , PIK3CG, PIK3R1, PIK3R2, PIK3R3, PIK3R4, PIK3R5, FGFR1, FGFR2, FGFR3 and / or FGFR4.Данное изобретение касается применения соединения 2,3-дигидроимидазо[1,2-c]хиназолина или фармацевтической композиции, которая его содержит, в качестве отдельного действующего вещества или комбинации а) указанного выше соединения или фармацевтической композиции, которая содержит указанное соединение, и б) одного или нескольких дополнительных действующих веществ для приготовления медикамента для лечения или про
