Moreover, we observed enhanced growth of untreated 451LU melanoma spheroids in stiffer gels (Section S7 in Supplemental Information S1, raw data in Supplemental Information S3, video in Supplemental Information S6) and further complemented this observation with spheroids consisting of two additional BRAF-mutated A375 (Raw data in Supplemental Information S4) and SK-MEL-2 cell lines (Raw data in Supplemental Information S5). Here, BRAF is linked to melanoma.