LRP1B and leukoencephalopathy with calcifications and cysts: Other frequently mutated genes included LRP1B, MSH3, FANCA, and NOTCH3 in cSCLC-LCC/LCNEC, and LRP1B, PIK3CA, RB1, and ARID1A in cSCLC-ADC/SCC (Additional file 2: Table S4).