Here, we report the effects of the WEE1 inhibitor MK1775 (AZD1775/Adavosertib) and the ATR inhibitor VE882 (VX-970/M6620/Berzosertib), alone and in combination, on the osteosarcoma cell line U2OS and on a panel of four different lung cancer cell lines with different sensitivities to the WEE1 inhibitor. This evidence concerns the gene ATR and osteosarcoma.